add code_size/code_hash fn in StackState trait ref: rust-ethereum/evm…

…#140

modules/evm/src/runner/stack.rs

@@ -21,7 +21,7 @@
 
 use crate::{
 	runner::{
-		state::{Accessed, CustomStackState, StackExecutor, StackState as StackStateT, StackSubstateMetadata},
+		state::{Accessed, StackExecutor, StackState as StackStateT, StackSubstateMetadata},
 		Runner as RunnerT, RunnerExtended,
 	},
 	AccountStorages, BalanceOf, CallInfo, Config, CreateInfo, Error, ExecutionInfo, Pallet, STORAGE_SIZE,
@@ -911,14 +911,12 @@ impl<'vicinity, 'config, T: Config> StackStateT<'config> for SubstrateStackState
 		self.substate
 			.recursive_is_cold(&|a: &Accessed| a.accessed_storage.contains(&(address, key)))
 	}
-}
 
-impl<'vicinity, 'config, T: Config> CustomStackState for SubstrateStackState<'vicinity, 'config, T> {
-	fn code_hash_at_address(&self, address: H160) -> H256 {
-		Pallet::<T>::code_hash_at_address(&address)
+	fn code_size(&self, address: H160) -> U256 {
+		Pallet::<T>::code_size_at_address(&address)
 	}
 
-	fn code_size_at_address(&self, address: H160) -> U256 {
-		Pallet::<T>::code_size_at_address(&address)
+	fn code_hash(&self, address: H160) -> H256 {
+		Pallet::<T>::code_hash_at_address(&address)
 	}
 }

modules/evm/src/runner/state.rs

@@ -308,12 +308,7 @@ impl<'config> StackSubstateMetadata<'config> {
 	}
 }
 
-pub trait CustomStackState {
-	fn code_hash_at_address(&self, address: H160) -> H256;
-	fn code_size_at_address(&self, address: H160) -> U256;
-}
-
-pub trait StackState<'config>: Backend + CustomStackState {
+pub trait StackState<'config>: Backend {
 	fn metadata(&self) -> &StackSubstateMetadata<'config>;
 	fn metadata_mut(&mut self) -> &mut StackSubstateMetadata<'config>;
 
@@ -336,6 +331,22 @@ pub trait StackState<'config>: Backend + CustomStackState {
 	fn transfer(&mut self, transfer: Transfer) -> Result<(), ExitError>;
 	fn reset_balance(&mut self, address: H160);
 	fn touch(&mut self, address: H160);
+
+	/// Fetch the code size of an address.
+	/// Provide a default implementation by fetching the code, but
+	/// can be customized to use a more performant approach that don't need to
+	/// fetch the code.
+	fn code_size(&self, address: H160) -> U256 {
+		U256::from(self.code(address).len())
+	}
+
+	/// Fetch the code hash of an address.
+	/// Provide a default implementation by fetching the code, but
+	/// can be customized to use a more performant approach that don't need to
+	/// fetch the code.
+	fn code_hash(&self, address: H160) -> H256 {
+		H256::from_slice(Keccak256::digest(self.code(address)).as_slice())
+	}
 }
 
 /// Data returned by a precompile on success.
@@ -1136,15 +1147,15 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet> Handler
 	}
 
 	fn code_size(&self, address: H160) -> U256 {
-		self.state.code_size_at_address(address)
+		self.state.code_size(address)
 	}
 
 	fn code_hash(&self, address: H160) -> H256 {
 		if !self.exists(address) {
 			return H256::default();
 		}
 
-		self.state.code_hash_at_address(address)
+		self.state.code_hash(address)
 	}
 
 	fn code(&self, address: H160) -> Vec<u8> {