perf(trie): avoid clearing already-cached sparse trie (#21702)

Co-authored-by: Amp <amp@ampcode.com>

crates/engine/tree/src/tree/payload_processor/mod.rs

@@ -39,7 +39,7 @@ use reth_trie_parallel::{
     proof_task::{ProofTaskCtx, ProofWorkerHandle},
     root::ParallelStateRootError,
 };
-use reth_trie_sparse::{ClearedSparseStateTrie, RevealableSparseTrie, SparseStateTrie};
+use reth_trie_sparse::{RevealableSparseTrie, SparseStateTrie};
 use reth_trie_sparse_parallel::{ParallelSparseTrie, ParallelismThresholds};
 use std::{
     collections::BTreeMap,
@@ -552,11 +552,11 @@ where
                     sparse_state_trie,
                 ))
             } else {
-                SpawnedSparseTrieTask::Cached(SparseTrieCacheTask::new_with_cleared_trie(
+                SpawnedSparseTrieTask::Cached(SparseTrieCacheTask::new_with_trie(
                     from_multi_proof,
                     proof_worker_handle,
                     trie_metrics.clone(),
-                    ClearedSparseStateTrie::from_state_trie(sparse_state_trie),
+                    sparse_state_trie,
                 ))
             };
 

crates/engine/tree/src/tree/payload_processor/sparse_trie.rs

@@ -26,8 +26,7 @@ use reth_trie_parallel::{
 use reth_trie_sparse::{
     errors::{SparseStateTrieResult, SparseTrieErrorKind},
     provider::{TrieNodeProvider, TrieNodeProviderFactory},
-    ClearedSparseStateTrie, LeafUpdate, SerialSparseTrie, SparseStateTrie, SparseTrie,
-    SparseTrieExt,
+    LeafUpdate, SerialSparseTrie, SparseStateTrie, SparseTrie, SparseTrieExt,
 };
 use revm_primitives::{hash_map::Entry, B256Map};
 use smallvec::SmallVec;
@@ -251,12 +250,12 @@ where
     A: SparseTrieExt + Default,
     S: SparseTrieExt + Default + Clone,
 {
-    /// Creates a new sparse trie, pre-populating with a [`ClearedSparseStateTrie`].
-    pub(super) fn new_with_cleared_trie(
+    /// Creates a new sparse trie, pre-populating with an existing [`SparseStateTrie`].
+    pub(super) fn new_with_trie(
         updates: CrossbeamReceiver<MultiProofMessage>,
         proof_worker_handle: ProofWorkerHandle,
         metrics: MultiProofTaskMetrics,
-        sparse_state_trie: ClearedSparseStateTrie<A, S>,
+        sparse_state_trie: SparseStateTrie<A, S>,
     ) -> Self {
         let (proof_result_tx, proof_result_rx) = crossbeam_channel::unbounded();
         Self {
@@ -264,7 +263,7 @@ where
             proof_result_rx,
             updates,
             proof_worker_handle,
-            trie: sparse_state_trie.into_inner(),
+            trie: sparse_state_trie,
             account_updates: Default::default(),
             storage_updates: Default::default(),
             pending_account_updates: Default::default(),

crates/trie/sparse/src/state.rs

@@ -23,48 +23,6 @@ use reth_trie_common::{
 use tracing::debug;
 use tracing::{instrument, trace};
 
-/// Provides type-safe re-use of cleared [`SparseStateTrie`]s, which helps to save allocations
-/// across payload runs.
-#[derive(Debug)]
-pub struct ClearedSparseStateTrie<
-    A = SerialSparseTrie, // Account trie implementation
-    S = SerialSparseTrie, // Storage trie implementation
->(SparseStateTrie<A, S>);
-
-impl<A, S> ClearedSparseStateTrie<A, S>
-where
-    A: SparseTrieTrait,
-    S: SparseTrieTrait,
-{
-    /// Creates a [`ClearedSparseStateTrie`] by clearing all the existing internal state of a
-    /// [`SparseStateTrie`] and then storing that instance for later re-use.
-    pub fn from_state_trie(mut trie: SparseStateTrie<A, S>) -> Self {
-        trie.state.clear();
-        trie.revealed_account_paths.clear();
-        trie.storage.clear();
-        trie.account_rlp_buf.clear();
-        Self(trie)
-    }
-
-    /// Returns the cleared [`SparseStateTrie`], consuming this instance.
-    pub fn into_inner(self) -> SparseStateTrie<A, S> {
-        self.0
-    }
-}
-
-impl<A, S> ClearedSparseStateTrie<A, S>
-where
-    A: SparseTrieTrait + SparseTrieExt + Default,
-    S: SparseTrieTrait + SparseTrieExt + Default + Clone,
-{
-    /// Shrink the cleared sparse trie's capacity to the given node and value size.
-    ///
-    /// Delegates to the inner `SparseStateTrie::shrink_to`.
-    pub fn shrink_to(&mut self, max_nodes: usize, max_values: usize) {
-        self.0.shrink_to(max_nodes, max_values);
-    }
-}
-
 #[derive(Debug)]
 /// Sparse state trie representing lazy-loaded Ethereum state trie.
 pub struct SparseStateTrie<