feat(root): support proof prefetch in the task

crates/engine/tree/src/tree/root.rs

@@ -1,9 +1,9 @@
 //! State root task related functionality.
 
-use alloy_primitives::map::HashSet;
+use alloy_primitives::{map::HashSet, Address};
 use derive_more::derive::Deref;
 use rayon::iter::{ParallelBridge, ParallelIterator};
-use reth_errors::ProviderError;
+use reth_errors::{ProviderError, ProviderResult};
 use reth_evm::system_calls::OnStateHook;
 use reth_provider::{
     providers::ConsistentDbView, BlockReader, DBProvider, DatabaseProviderFactory,
@@ -108,6 +108,8 @@ impl<Factory> StateRootConfig<Factory> {
 #[derive(Debug)]
 #[allow(dead_code)]
 pub enum StateRootMessage<BPF: BlindedProviderFactory> {
+    /// Prefetch proof targets
+    PrefetchProofs(HashSet<Address>),
     /// New state update from transaction execution
     StateUpdate(EvmState),
     /// Proof calculation completed for a specific state update
@@ -340,6 +342,29 @@ where
         }
     }
 
+    /// Handles request for proof prefetch.
+    fn on_prefetch_proof(
+        scope: &rayon::Scope<'env>,
+        config: StateRootConfig<Factory>,
+        targets: HashSet<Address>,
+        fetched_proof_targets: &mut MultiProofTargets,
+        proof_sequence_number: u64,
+        state_root_message_sender: Sender<StateRootMessage<BPF>>,
+    ) {
+        let proof_targets =
+            targets.into_iter().map(|address| (keccak256(address), Default::default())).collect();
+        extend_multi_proof_targets_ref(fetched_proof_targets, &proof_targets);
+
+        Self::spawn_multiproof(
+            scope,
+            config,
+            Default::default(),
+            proof_targets,
+            proof_sequence_number,
+            state_root_message_sender,
+        );
+    }
+
     /// Handles state updates.
     ///
     /// Returns proof targets derived from the state update.
@@ -356,46 +381,39 @@ where
         let proof_targets = get_proof_targets(&hashed_state_update, fetched_proof_targets);
         extend_multi_proof_targets_ref(fetched_proof_targets, &proof_targets);
 
+        Self::spawn_multiproof(
+            scope,
+            config,
+            hashed_state_update,
+            proof_targets,
+            proof_sequence_number,
+            state_root_message_sender,
+        );
+    }
+
+    fn spawn_multiproof(
+        scope: &rayon::Scope<'env>,
+        config: StateRootConfig<Factory>,
+        hashed_state_update: HashedPostState,
+        proof_targets: MultiProofTargets,
+        proof_sequence_number: u64,
+        state_root_message_sender: Sender<StateRootMessage<BPF>>,
+    ) {
         // Dispatch proof gathering for this state update
-        scope.spawn(move |_| {
-            let provider = match config.consistent_view.provider_ro() {
-                Ok(provider) => provider,
-                Err(error) => {
-                    error!(target: "engine::root", ?error, "Could not get provider");
-                    let _ = state_root_message_sender
-                        .send(StateRootMessage::ProofCalculationError(error));
-                    return;
-                }
-            };
-
-            // TODO: replace with parallel proof
-            let result = Proof::from_tx(provider.tx_ref())
-                .with_trie_cursor_factory(InMemoryTrieCursorFactory::new(
-                    DatabaseTrieCursorFactory::new(provider.tx_ref()),
-                    &config.nodes_sorted,
-                ))
-                .with_hashed_cursor_factory(HashedPostStateCursorFactory::new(
-                    DatabaseHashedCursorFactory::new(provider.tx_ref()),
-                    &config.state_sorted,
-                ))
-                .with_prefix_sets_mut(config.prefix_sets.as_ref().clone())
-                .with_branch_node_hash_masks(true)
-                .multiproof(proof_targets.clone());
-            match result {
-                Ok(proof) => {
-                    let _ = state_root_message_sender.send(StateRootMessage::ProofCalculated(
-                        Box::new(ProofCalculated {
-                            state_update: hashed_state_update,
-                            targets: proof_targets,
-                            proof,
-                            sequence_number: proof_sequence_number,
-                        }),
-                    ));
-                }
-                Err(error) => {
-                    let _ = state_root_message_sender
-                        .send(StateRootMessage::ProofCalculationError(error.into()));
-                }
+        scope.spawn(move |_| match calculate_multiproof(config, proof_targets.clone()) {
+            Ok(proof) => {
+                let _ = state_root_message_sender.send(StateRootMessage::ProofCalculated(
+                    Box::new(ProofCalculated {
+                        state_update: hashed_state_update,
+                        targets: proof_targets,
+                        proof,
+                        sequence_number: proof_sequence_number,
+                    }),
+                ));
+            }
+            Err(error) => {
+                let _ =
+                    state_root_message_sender.send(StateRootMessage::ProofCalculationError(error));
             }
         });
     }
@@ -486,6 +504,21 @@ where
         loop {
             match self.rx.recv() {
                 Ok(message) => match message {
+                    StateRootMessage::PrefetchProofs(targets) => {
+                        debug!(
+                            target: "engine::root",
+                            len = targets.len(),
+                            "Prefetching proofs"
+                        );
+                        Self::on_prefetch_proof(
+                            scope,
+                            self.config.clone(),
+                            targets,
+                            &mut self.fetched_proof_targets,
+                            self.proof_sequencer.next_sequence(),
+                            self.tx.clone(),
+                        );
+                    }
                     StateRootMessage::StateUpdate(update) => {
                         if updates_received == 0 {
                             first_update_time = Some(Instant::now());
@@ -681,6 +714,31 @@ fn get_proof_targets(
     targets
 }
 
+/// Calculate multiproof for the targets.
+#[inline]
+fn calculate_multiproof<Factory>(
+    config: StateRootConfig<Factory>,
+    proof_targets: MultiProofTargets,
+) -> ProviderResult<MultiProof>
+where
+    Factory: DatabaseProviderFactory<Provider: BlockReader> + StateCommitmentProvider,
+{
+    let provider = config.consistent_view.provider_ro()?;
+
+    Ok(Proof::from_tx(provider.tx_ref())
+        .with_trie_cursor_factory(InMemoryTrieCursorFactory::new(
+            DatabaseTrieCursorFactory::new(provider.tx_ref()),
+            &config.nodes_sorted,
+        ))
+        .with_hashed_cursor_factory(HashedPostStateCursorFactory::new(
+            DatabaseHashedCursorFactory::new(provider.tx_ref()),
+            &config.state_sorted,
+        ))
+        .with_prefix_sets_mut(config.prefix_sets.as_ref().clone())
+        .with_branch_node_hash_masks(true)
+        .multiproof(proof_targets)?)
+}
+
 /// Updates the sparse trie with the given proofs and state, and returns the updated trie and the
 /// time it took.
 fn update_sparse_trie<