From 131d2745d3305fce8096d1fe52674d62753ab50e Mon Sep 17 00:00:00 2001
From: Hai Nguyen Quang <hai@caliber.build>
Date: Tue, 20 Aug 2024 22:03:36 +0700
Subject: [PATCH] perf: simplify basic account in mv memory

---
 src/lib.rs  |  2 +-
 src/pevm.rs |  6 ++----
 src/vm.rs   | 21 +++++++++++----------
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 8ceabea4..02dacd68 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -65,7 +65,7 @@ type BuildIdentityHasher = BuildHasherDefault<IdentityHasher>;
 // matches & potentially dangerous mismatch mistakes.
 #[derive(Debug, Clone)]
 enum MemoryValue {
-    Basic(Option<AccountBasic>),
+    Basic(AccountBasic),
     CodeHash(Option<B256>),
     Storage(U256),
     // We lazily update the beneficiary balance to avoid continuous
diff --git a/src/pevm.rs b/src/pevm.rs
index c35c799b..90e4cd17 100644
--- a/src/pevm.rs
+++ b/src/pevm.rs
@@ -267,12 +267,10 @@ pub fn execute_revm_parallel<S: Storage + Send + Sync, C: PevmChain + Send + Syn
             for (tx_idx, memory_entry) in write_history {
                 match memory_entry {
                     MemoryEntry::Data(_, MemoryValue::Basic(info)) => {
-                        if let Some(info) = info {
-                            balance = info.balance;
-                            nonce = info.nonce;
-                        }
                         // TODO: Assert that there must be no self-destructed
                         // accounts here.
+                        balance = info.balance;
+                        nonce = info.nonce;
                     }
                     MemoryEntry::Data(_, MemoryValue::LazyRecipient(addition)) => {
                         balance += addition;
diff --git a/src/vm.rs b/src/vm.rs
index 59ee01f1..c258d55a 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -295,10 +295,11 @@ impl<'a, S: Storage, C: PevmChain> Database for VmDb<'a, S, C> {
                             new_origins.push(origin);
                             match value {
                                 MemoryValue::Basic(basic) => {
-                                    if basic.is_none() {
-                                        return Err(ReadError::SelfDestructedAccount);
-                                    }
-                                    final_account.clone_from(basic);
+                                    // TODO: Return [ReadError::SelfDestructedAccount] if [basic] is
+                                    // empty?
+                                    // For now we are betting on [code_hash] triggering the sequential
+                                    // fallback when we read a self-destructed contract.
+                                    final_account = Some(basic.clone());
                                     break;
                                 }
                                 MemoryValue::LazyRecipient(addition) => {
@@ -598,7 +599,9 @@ impl<'a, S: Storage, C: PevmChain> Vm<'a, S, C> {
                 let mut lazy_addresses = NewLazyAddresses::new();
                 for (address, account) in result_and_state.state.iter() {
                     if account.is_selfdestructed() {
-                        write_set.push((self.hash_basic(address), MemoryValue::Basic(None)));
+                        // TODO: Write an empty basic account to [write_set]?
+                        // For now we are betting on [code_hash] triggering the sequential
+                        // fallback when we read a self-destructed contract.
                         write_set.push((
                             self.hasher.hash_one(MemoryLocation::CodeHash(*address)),
                             MemoryValue::CodeHash(None),
@@ -638,10 +641,10 @@ impl<'a, S: Storage, C: PevmChain> Vm<'a, S, C> {
                             } else {
                                 write_set.push((
                                     account_location_hash,
-                                    MemoryValue::Basic(Some(AccountBasic {
+                                    MemoryValue::Basic(AccountBasic {
                                         balance: account.info.balance,
                                         nonce: account.info.nonce,
-                                    })),
+                                    }),
                                 ));
                             }
                         }
@@ -744,9 +747,7 @@ impl<'a, S: Storage, C: PevmChain> Vm<'a, S, C> {
                 .find(|(location, _)| location == &recipient)
             {
                 match value {
-                    MemoryValue::Basic(basic) => {
-                        basic.get_or_insert(AccountBasic::default()).balance += amount
-                    }
+                    MemoryValue::Basic(basic) => basic.balance += amount,
                     MemoryValue::LazySender(addition) => *addition -= amount,
                     MemoryValue::LazyRecipient(addition) => *addition += amount,
                     _ => unreachable!(), // TODO: Better error handling