From 00bebfd64d3b743bfc42c734390697111d305a8d Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Thu, 7 Sep 2023 14:21:00 +0200
Subject: [PATCH] perf: small access list perf (#4505)

---
 .../primitives/src/transaction/access_list.rs | 20 ++++++++++---------
 .../revm/revm-inspectors/src/access_list.rs   |  4 ++--
 crates/rpc/rpc/src/eth/api/call.rs            |  5 +++--
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/crates/primitives/src/transaction/access_list.rs b/crates/primitives/src/transaction/access_list.rs
index a86b33b69e..11b119898a 100644
--- a/crates/primitives/src/transaction/access_list.rs
+++ b/crates/primitives/src/transaction/access_list.rs
@@ -48,15 +48,17 @@ pub struct AccessList(
 impl AccessList {
     /// Converts the list into a vec, expected by revm
     pub fn flattened(self) -> Vec<(Address, Vec<U256>)> {
-        self.0
-            .into_iter()
-            .map(|item| {
-                (
-                    item.address,
-                    item.storage_keys.into_iter().map(|slot| U256::from_be_bytes(slot.0)).collect(),
-                )
-            })
-            .collect()
+        self.flatten().collect()
+    }
+
+    /// Returns an iterator over the list's addresses and storage keys.
+    pub fn flatten(self) -> impl Iterator<Item = (Address, Vec<U256>)> {
+        self.0.into_iter().map(|item| {
+            (
+                item.address,
+                item.storage_keys.into_iter().map(|slot| U256::from_be_bytes(slot.0)).collect(),
+            )
+        })
     }
 
     /// Calculates a heuristic for the in-memory size of the [AccessList].
diff --git a/crates/revm/revm-inspectors/src/access_list.rs b/crates/revm/revm-inspectors/src/access_list.rs
index 41faf88a2b..bc9d641d71 100644
--- a/crates/revm/revm-inspectors/src/access_list.rs
+++ b/crates/revm/revm-inspectors/src/access_list.rs
@@ -31,8 +31,8 @@ impl AccessListInspector {
             excluded: [from, to].iter().chain(precompiles.iter()).copied().collect(),
             access_list: access_list
                 .0
-                .iter()
-                .map(|v| (v.address, v.storage_keys.iter().copied().collect()))
+                .into_iter()
+                .map(|v| (v.address, v.storage_keys.into_iter().collect()))
                 .collect(),
         }
     }
diff --git a/crates/rpc/rpc/src/eth/api/call.rs b/crates/rpc/rpc/src/eth/api/call.rs
index 6bf638cf5a..6f27d1a3b3 100644
--- a/crates/rpc/rpc/src/eth/api/call.rs
+++ b/crates/rpc/rpc/src/eth/api/call.rs
@@ -340,7 +340,7 @@ where
 
     pub(crate) async fn create_access_list_at(
         &self,
-        request: CallRequest,
+        mut request: CallRequest,
         at: Option<BlockId>,
     ) -> EthResult<AccessList> {
         let block_id = at.unwrap_or(BlockId::Number(BlockNumberOrTag::Latest));
@@ -373,7 +373,8 @@ where
             get_contract_address(from, nonce).into()
         };
 
-        let initial = request.access_list.clone().unwrap_or_default();
+        // can consume the list since we're not using the request anymore
+        let initial = request.access_list.take().unwrap_or_default();
 
         let precompiles = get_precompiles(&env.cfg.spec_id);
         let mut inspector = AccessListInspector::new(initial, from, to, precompiles);