From 02baf408a3b8b7f165507259c465a3f44d221143 Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Fri, 12 Apr 2024 19:27:44 +0200
Subject: [PATCH] feat: port helpers for accesslist (#508)

* feat: port helpers for accesslist

* chore: touchups
---
 crates/eips/src/eip2930.rs | 45 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/crates/eips/src/eip2930.rs b/crates/eips/src/eip2930.rs
index 2570df132bb..ee8684d1c56 100644
--- a/crates/eips/src/eip2930.rs
+++ b/crates/eips/src/eip2930.rs
@@ -9,7 +9,7 @@ use alloc::vec::Vec;
 
 use alloy_primitives::{Address, B256, U256};
 use alloy_rlp::{RlpDecodable, RlpDecodableWrapper, RlpEncodable, RlpEncodableWrapper};
-use core::mem;
+use core::{mem, ops::Deref};
 
 /// A list of addresses and storage keys that the transaction plans to access.
 /// Accesses outside the list are possible, but become more expensive.
@@ -70,6 +70,14 @@ impl From<AccessList> for Vec<AccessListItem> {
     }
 }
 
+impl Deref for AccessList {
+    type Target = Vec<AccessListItem>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 impl AccessList {
     /// Converts the list into a vec, expected by revm
     pub fn flattened(&self) -> Vec<(Address, Vec<U256>)> {
@@ -101,6 +109,41 @@ impl AccessList {
         })
     }
 
+    /// Returns the position of the given address in the access list, if present.
+    fn index_of_address(&self, address: Address) -> Option<usize> {
+        self.iter().position(|item| item.address == address)
+    }
+
+    /// Checks if a specific storage slot within an account is present in the access list.
+    ///
+    /// Returns a tuple with flags for the presence of the account and the slot.
+    pub fn contains_storage(&self, address: Address, slot: B256) -> (bool, bool) {
+        self.index_of_address(address)
+            .map_or((false, false), |idx| (true, self.contains_storage_key_at_index(slot, idx)))
+    }
+
+    /// Checks if the access list contains the specified address.
+    pub fn contains_address(&self, address: Address) -> bool {
+        self.iter().any(|item| item.address == address)
+    }
+
+    /// Checks if the storage keys at the given index within an account are present in the access
+    /// list.
+    fn contains_storage_key_at_index(&self, slot: B256, index: usize) -> bool {
+        self.get(index).map_or(false, |entry| {
+            entry.storage_keys.iter().any(|storage_key| *storage_key == slot)
+        })
+    }
+
+    /// Adds an address to the access list and returns `true` if the operation results in a change,
+    /// indicating that the address was not previously present.
+    pub fn add_address(&mut self, address: Address) -> bool {
+        !self.contains_address(address) && {
+            self.0.push(AccessListItem { address, storage_keys: Vec::new() });
+            true
+        }
+    }
+
     /// Calculates a heuristic for the in-memory size of the [AccessList].
     #[inline]
     pub fn size(&self) -> usize {