From ea3d4663ae2550622040c1ff9b212bcfde04dfe3 Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Tue, 20 Jan 2026 14:34:41 +0100
Subject: [PATCH] perf(trie): use HashMap reserve heuristic in
 MultiProof::extend (#21199)

---
 crates/trie/common/src/proofs.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/crates/trie/common/src/proofs.rs b/crates/trie/common/src/proofs.rs
index c3eab92011..b65b3ec966 100644
--- a/crates/trie/common/src/proofs.rs
+++ b/crates/trie/common/src/proofs.rs
@@ -267,6 +267,12 @@ impl MultiProof {
         self.account_subtree.extend_from(other.account_subtree);
         self.branch_node_masks.extend(other.branch_node_masks);
 
+        let reserve = if self.storages.is_empty() {
+            other.storages.len()
+        } else {
+            other.storages.len().div_ceil(2)
+        };
+        self.storages.reserve(reserve);
         for (hashed_address, storage) in other.storages {
             match self.storages.entry(hashed_address) {
                 hash_map::Entry::Occupied(mut entry) => {
@@ -390,6 +396,12 @@ impl DecodedMultiProof {
         self.account_subtree.extend_from(other.account_subtree);
         self.branch_node_masks.extend(other.branch_node_masks);
 
+        let reserve = if self.storages.is_empty() {
+            other.storages.len()
+        } else {
+            other.storages.len().div_ceil(2)
+        };
+        self.storages.reserve(reserve);
         for (hashed_address, storage) in other.storages {
             match self.storages.entry(hashed_address) {
                 hash_map::Entry::Occupied(mut entry) => {