From b3b636e77500f475050ffb4cebd1632650c2a198 Mon Sep 17 00:00:00 2001
From: Lucas Fiegl <iovoid@users.noreply.github.com>
Date: Tue, 4 Nov 2025 09:54:42 -0300
Subject: [PATCH] reuse stack pool

---
 crates/vm/backends/levm/mod.rs | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/crates/vm/backends/levm/mod.rs b/crates/vm/backends/levm/mod.rs
index 08aedca3601..2792b10b5e3 100644
--- a/crates/vm/backends/levm/mod.rs
+++ b/crates/vm/backends/levm/mod.rs
@@ -18,6 +18,7 @@ use ethrex_common::{
     },
 };
 use ethrex_levm::EVMConfig;
+use ethrex_levm::call_frame::Stack;
 use ethrex_levm::constants::{SYS_CALL_GAS_LIMIT, TX_BASE_COST};
 use ethrex_levm::db::gen_db::GeneralizedDatabase;
 use ethrex_levm::errors::{InternalError, TxValidationError};
@@ -91,13 +92,22 @@ impl LEVM {
     ) -> Result<BlockExecutionResult, EvmError> {
         Self::prepare_block(block, db, vm_type)?;
 
+        let mut shared_stack_pool = Vec::with_capacity(1024);
+
         let mut receipts = Vec::new();
         let mut cumulative_gas_used = 0;
 
         for (tx, tx_sender) in block.body.get_transactions_with_sender().map_err(|error| {
             EvmError::Transaction(format!("Couldn't recover addresses with error: {error}"))
         })? {
-            let report = Self::execute_tx(tx, tx_sender, &block.header, db, vm_type)?;
+            let report = Self::execute_tx_in_block(
+                tx,
+                tx_sender,
+                &block.header,
+                db,
+                vm_type,
+                &mut shared_stack_pool,
+            )?;
             LEVM::send_state_transitions_tx(&merkleizer, db, queue_length)?;
 
             cumulative_gas_used += report.gas_used;
@@ -215,6 +225,26 @@ impl LEVM {
         vm.execute().map_err(VMError::into)
     }
 
+    pub fn execute_tx_in_block(
+        // The transaction to execute.
+        tx: &Transaction,
+        // The transactions recovered address
+        tx_sender: Address,
+        // The block header for the current block.
+        block_header: &BlockHeader,
+        db: &mut GeneralizedDatabase,
+        vm_type: VMType,
+        stack_pool: &mut Vec<Stack>,
+    ) -> Result<ExecutionReport, EvmError> {
+        let env = Self::setup_env(tx, tx_sender, block_header, db, vm_type)?;
+        let mut vm = VM::new(env, db, tx, LevmCallTracer::disabled(), vm_type)?;
+
+        std::mem::swap(&mut vm.stack_pool, stack_pool);
+        let result = vm.execute().map_err(VMError::into);
+        std::mem::swap(&mut vm.stack_pool, stack_pool);
+        result
+    }
+
     pub fn undo_last_tx(db: &mut GeneralizedDatabase) -> Result<(), EvmError> {
         db.undo_last_transaction()?;
         Ok(())