[autoopt] 20260414-008-sparse-prune-retained-slices

crates/trie/sparse/src/arena/mod.rs

@@ -2670,8 +2670,14 @@ impl SparseTrie for ArenaParallelSparseTrie {
             return 0;
         }
 
-        let mut retained_leaves = retained_leaves.to_vec();
-        retained_leaves.sort_unstable();
+        let retained_leaves = if retained_leaves.windows(2).all(|w| w[0] <= w[1]) {
+            Cow::Borrowed(retained_leaves)
+        } else {
+            let mut retained = retained_leaves.to_vec();
+            retained.sort_unstable();
+            retained.dedup();
+            Cow::Owned(retained)
+        };
 
         let threshold = self.parallelism_thresholds.min_leaves_for_prune;
 

crates/trie/sparse/src/parallel.rs

@@ -1158,8 +1158,14 @@ impl SparseTrie for ParallelSparseTrie {
         #[cfg(feature = "trie-debug")]
         self.debug_recorder.reset();
 
-        let mut retained_leaves = retained_leaves.to_vec();
-        retained_leaves.sort_unstable();
+        let retained_leaves = if retained_leaves.windows(2).all(|w| w[0] <= w[1]) {
+            Cow::Borrowed(retained_leaves)
+        } else {
+            let mut retained = retained_leaves.to_vec();
+            retained.sort_unstable();
+            retained.dedup();
+            Cow::Owned(retained)
+        };
 
         let mut effective_pruned_roots = Vec::<Nibbles>::new();
         let mut stack: SmallVec<[Nibbles; 32]> = SmallVec::new();

crates/trie/sparse/src/state.rs

@@ -875,8 +875,9 @@ where
         self.hot_accounts_lfu.decay_and_evict(max_hot_accounts);
         let retained = self.hot_slots_lfu.retained_slots_by_address();
 
-        let retained_account_paths: Vec<Nibbles> =
+        let mut retained_account_paths: Vec<Nibbles> =
             self.hot_accounts_lfu.keys().map(|k| Nibbles::unpack(*k)).collect();
+        retained_account_paths.sort_unstable();
 
         let retained_accounts = retained_account_paths.len();
         let retained_storage_tries = retained.len();