fix(levm): make account_exists() return a result (#2983)

**Motivation**

<!-- Why does this pull request exist? What are its goals? -->
- The goal is to return an error if there's a problem when accessing the
database instead of panicking.

**Description**

<!-- A clear and concise general description of the changes this PR
introduces -->

<!-- Link to issues: Resolves #111, Resolves #222 -->

Co-authored-by: Lucas Fiegl <[email protected]>

Author: JereSalo

cmd/ethrex_replay/src/rpc/db.rs

@@ -412,7 +412,7 @@ impl RpcDB {
 }
 
 impl LevmDatabase for RpcDB {
-    fn account_exists(&self, address: Address) -> bool {
+    fn account_exists(&self, address: Address) -> Result<bool, DatabaseError> {
         // look into the cache
         {
             if self
@@ -422,11 +422,12 @@ impl LevmDatabase for RpcDB {
                 .get(&address)
                 .is_some_and(|account| matches!(account, Account::Existing { .. }))
             {
-                return true;
+                return Ok(true);
             }
         }
-        self.fetch_account_blocking(address, &[], false)
-            .is_ok_and(|account| matches!(account, Account::Existing { .. }))
+        Ok(self
+            .fetch_account_blocking(address, &[], false)
+            .is_ok_and(|account| matches!(account, Account::Existing { .. })))
     }
 
     fn get_account_code(&self, _code_hash: H256) -> Result<Bytes, DatabaseError> {

crates/vm/backends/levm/db.rs

@@ -44,8 +44,11 @@ impl LevmDatabase for DatabaseLogger {
             .get_account(address)
     }
 
-    fn account_exists(&self, address: CoreAddress) -> bool {
-        self.store.lock().unwrap().account_exists(address)
+    fn account_exists(&self, address: CoreAddress) -> Result<bool, DatabaseError> {
+        self.store
+            .lock()
+            .map_err(|_| DatabaseError::Custom("Could not lock mutex".to_string()))?
+            .account_exists(address)
     }
 
     fn get_storage_value(
@@ -114,9 +117,10 @@ impl LevmDatabase for DynVmDatabase {
         ))
     }
 
-    fn account_exists(&self, address: CoreAddress) -> bool {
-        let acc_info = <dyn VmDatabase>::get_account_info(self.as_ref(), address).unwrap();
-        acc_info.is_some()
+    fn account_exists(&self, address: CoreAddress) -> Result<bool, DatabaseError> {
+        let acc_info = <dyn VmDatabase>::get_account_info(self.as_ref(), address)
+            .map_err(|e| DatabaseError::Custom(e.to_string()))?;
+        Ok(acc_info.is_some())
     }
 
     fn get_storage_value(
@@ -172,8 +176,8 @@ impl LevmDatabase for ProverDB {
         ))
     }
 
-    fn account_exists(&self, address: CoreAddress) -> bool {
-        self.accounts.contains_key(&address)
+    fn account_exists(&self, address: CoreAddress) -> Result<bool, DatabaseError> {
+        Ok(self.accounts.contains_key(&address))
     }
 
     fn get_block_hash(&self, block_number: u64) -> Result<CoreH256, DatabaseError> {

crates/vm/backends/levm/mod.rs

@@ -260,7 +260,7 @@ impl LEVM {
             // If account is now empty and it didn't exist in the trie before, no need to make changes.
             // This check is necessary just in case we keep empty accounts in the trie. If we're sure we don't, this code can be removed.
             // `initial_state_account.is_empty()` check can be removed but I added it because it's short-circuiting, this way we don't hit the db very often.
-            if removed && initial_state_account.is_empty() && !db.store.account_exists(*address) {
+            if removed && initial_state_account.is_empty() && !db.store.account_exists(*address)? {
                 continue;
             }
 

crates/vm/levm/src/db/mod.rs

@@ -14,7 +14,7 @@ pub trait Database: Send + Sync {
     fn get_account(&self, address: Address) -> Result<Account, DatabaseError>;
     fn get_storage_value(&self, address: Address, key: H256) -> Result<U256, DatabaseError>;
     fn get_block_hash(&self, block_number: u64) -> Result<H256, DatabaseError>;
-    fn account_exists(&self, address: Address) -> bool;
+    fn account_exists(&self, address: Address) -> Result<bool, DatabaseError>;
     fn get_chain_config(&self) -> Result<ChainConfig, DatabaseError>;
     fn get_account_code(&self, code_hash: H256) -> Result<Bytes, DatabaseError>;
 }