Initital implementation of overlayed backend

interpreter/Cargo.toml

@@ -15,6 +15,7 @@ scale-codec = { package = "parity-scale-codec", version = "3.2", default-feature
 scale-info = { version = "2.3", default-features = false, features = ["derive"], optional = true }
 serde = { version = "1.0", default-features = false, features = ["derive"], optional = true }
 sha3 = { version = "0.10", default-features = false }
+auto_impl = "1.1"
 
 [dev-dependencies]
 hex = "0.4"

interpreter/src/runtime.rs

@@ -75,6 +75,7 @@ pub struct Log {
 	pub data: Vec<u8>,
 }
 
+#[auto_impl::auto_impl(&, Box)]
 pub trait RuntimeEnvironment {
 	/// Get environmental block hash.
 	fn block_hash(&self, number: U256) -> H256;
@@ -96,6 +97,7 @@ pub trait RuntimeEnvironment {
 	fn chain_id(&self) -> U256;
 }
 
+#[auto_impl::auto_impl(&, Box)]
 pub trait RuntimeBaseBackend {
 	/// Get balance of address.
 	fn balance(&self, address: H160) -> U256;

jsontests/src/hash.rs

@@ -66,7 +66,6 @@ impl rlp::Decodable for TrieAccount {
 
 pub fn state_root(backend: &InMemoryBackend) -> H256 {
 	let tree = backend
-		.current_layer()
 		.state
 		.iter()
 		.map(|(address, account)| {

jsontests/src/in_memory.rs

@@ -1,12 +1,6 @@
-use evm::{
-	ExitError, ExitException, Log, MergeStrategy, RuntimeBackend, RuntimeBaseBackend,
-	RuntimeEnvironment, TransactionalBackend,
-};
+use evm::{backend::OverlayedChangeSet, RuntimeBaseBackend, RuntimeEnvironment};
 use primitive_types::{H160, H256, U256};
-use std::{
-	collections::{BTreeMap, BTreeSet},
-	mem,
-};
+use std::collections::BTreeMap;
 
 #[derive(Clone, Debug)]
 pub struct InMemoryEnvironment {
@@ -27,7 +21,6 @@ pub struct InMemoryAccount {
 	pub code: Vec<u8>,
 	pub nonce: U256,
 	pub storage: BTreeMap<H256, H256>,
-	pub original_storage: BTreeMap<H256, H256>,
 }
 
 #[derive(Clone, Debug)]
@@ -36,38 +29,42 @@ pub struct InMemorySuicideInfo {
 }
 
 #[derive(Clone, Debug)]
-pub struct InMemoryLayer {
+pub struct InMemoryBackend {
+	pub environment: InMemoryEnvironment,
 	pub state: BTreeMap<H160, InMemoryAccount>,
-	pub logs: Vec<Log>,
-	pub suicides: Vec<InMemorySuicideInfo>,
-	pub hots: BTreeSet<(H160, Option<H256>)>,
 }
 
-impl InMemoryLayer {
-	pub fn clear_pending(&mut self) {
-		self.hots.clear();
+impl InMemoryBackend {
+	pub fn apply_overlayed(&mut self, changeset: &OverlayedChangeSet) {
+		for (address, balance) in changeset.balances.clone() {
+			self.state.entry(address).or_default().balance = balance;
+		}
 
-		let mut suicides = Vec::new();
-		mem::swap(&mut suicides, &mut self.suicides);
-		for suicide in suicides {
-			self.state.remove(&suicide.address);
+		for (address, code) in changeset.codes.clone() {
+			self.state.entry(address).or_default().code = code;
 		}
-	}
-}
 
-#[derive(Clone, Debug)]
-pub struct InMemoryBackend {
-	pub environment: InMemoryEnvironment,
-	pub layers: Vec<InMemoryLayer>,
-}
+		for (address, nonce) in changeset.nonces.clone() {
+			self.state.entry(address).or_default().nonce = nonce;
+		}
 
-impl InMemoryBackend {
-	pub fn current_layer(&self) -> &InMemoryLayer {
-		self.layers.last().expect("current layer exists")
-	}
+		for address in changeset.storage_resets.clone() {
+			self.state.entry(address).or_default().storage = BTreeMap::new();
+		}
+
+		for ((address, key), value) in changeset.storages.clone() {
+			let account = self.state.entry(address).or_default();
 
-	pub fn current_layer_mut(&mut self) -> &mut InMemoryLayer {
-		self.layers.last_mut().expect("current layer exists")
+			if value == H256::default() {
+				account.storage.remove(&key);
+			} else {
+				account.storage.insert(key, value);
+			}
+		}
+
+		for address in changeset.deletes.clone() {
+			self.state.remove(&address);
+		}
 	}
 }
 
@@ -115,30 +112,27 @@ impl RuntimeEnvironment for InMemoryBackend {
 
 impl RuntimeBaseBackend for InMemoryBackend {
 	fn balance(&self, address: H160) -> U256 {
-		self.current_layer()
-			.state
+		self.state
 			.get(&address)
 			.cloned()
 			.unwrap_or(Default::default())
 			.balance
 	}
 
 	fn code(&self, address: H160) -> Vec<u8> {
-		self.current_layer()
-			.state
+		self.state
 			.get(&address)
 			.cloned()
 			.unwrap_or(Default::default())
 			.code
 	}
 
 	fn exists(&self, address: H160) -> bool {
-		self.current_layer().state.get(&address).is_some()
+		self.state.get(&address).is_some()
 	}
 
 	fn storage(&self, address: H160, index: H256) -> H256 {
-		self.current_layer()
-			.state
+		self.state
 			.get(&address)
 			.cloned()
 			.unwrap_or(Default::default())
@@ -149,133 +143,10 @@ impl RuntimeBaseBackend for InMemoryBackend {
 	}
 
 	fn nonce(&self, address: H160) -> U256 {
-		self.current_layer()
-			.state
+		self.state
 			.get(&address)
 			.cloned()
 			.unwrap_or(Default::default())
 			.nonce
 	}
 }
-
-impl RuntimeBackend for InMemoryBackend {
-	fn original_storage(&self, address: H160, index: H256) -> H256 {
-		self.current_layer()
-			.state
-			.get(&address)
-			.cloned()
-			.unwrap_or(Default::default())
-			.original_storage
-			.get(&index)
-			.cloned()
-			.unwrap_or(H256::default())
-	}
-
-	fn deleted(&self, address: H160) -> bool {
-		self.current_layer()
-			.suicides
-			.iter()
-			.any(|suicide| suicide.address == address)
-	}
-
-	fn is_cold(&self, address: H160, index: Option<H256>) -> bool {
-		!self.current_layer().hots.contains(&(address, index))
-	}
-
-	fn mark_hot(&mut self, address: H160, index: Option<H256>) {
-		self.current_layer_mut().hots.insert((address, index));
-	}
-
-	fn set_storage(&mut self, address: H160, index: H256, value: H256) -> Result<(), ExitError> {
-		let entry = self.current_layer_mut().state.entry(address).or_default();
-
-		if value == H256::default() {
-			entry.storage.remove(&index);
-		} else {
-			entry.storage.insert(index, value);
-		}
-		Ok(())
-	}
-
-	fn log(&mut self, log: Log) -> Result<(), ExitError> {
-		self.current_layer_mut().logs.push(log);
-		Ok(())
-	}
-
-	fn mark_delete(&mut self, address: H160) {
-		self.current_layer_mut()
-			.suicides
-			.push(InMemorySuicideInfo { address });
-	}
-
-	fn reset_storage(&mut self, address: H160) {
-		self.current_layer_mut()
-			.state
-			.entry(address)
-			.or_default()
-			.storage = Default::default();
-	}
-
-	fn set_code(&mut self, address: H160, code: Vec<u8>) -> Result<(), ExitError> {
-		self.current_layer_mut()
-			.state
-			.entry(address)
-			.or_default()
-			.code = code;
-
-		Ok(())
-	}
-
-	fn reset_balance(&mut self, address: H160) {
-		self.current_layer_mut()
-			.state
-			.entry(address)
-			.or_default()
-			.balance = U256::zero();
-	}
-
-	fn withdrawal(&mut self, source: H160, value: U256) -> Result<(), ExitError> {
-		let source = self.current_layer_mut().state.entry(source).or_default();
-		if source.balance < value {
-			return Err(ExitException::OutOfFund.into());
-		}
-		source.balance -= value;
-		Ok(())
-	}
-
-	fn deposit(&mut self, target: H160, value: U256) {
-		if value == U256::zero() {
-			return;
-		}
-
-		self.current_layer_mut()
-			.state
-			.entry(target)
-			.or_default()
-			.balance += value;
-	}
-
-	fn inc_nonce(&mut self, address: H160) -> Result<(), ExitError> {
-		let entry = self.current_layer_mut().state.entry(address).or_default();
-		entry.nonce = entry.nonce.saturating_add(U256::one());
-		Ok(())
-	}
-}
-
-impl TransactionalBackend for InMemoryBackend {
-	fn push_substate(&mut self) {
-		let layer = self.current_layer().clone();
-		self.layers.push(layer);
-	}
-
-	fn pop_substate(&mut self, strategy: MergeStrategy) {
-		let layer = self.layers.pop().expect("current layer exist");
-
-		match strategy {
-			MergeStrategy::Commit => {
-				*self.current_layer_mut() = layer;
-			}
-			MergeStrategy::Discard | MergeStrategy::Revert => (),
-		}
-	}
-}

jsontests/src/run.rs

@@ -1,6 +1,7 @@
 use crate::error::{Error, TestError};
-use crate::in_memory::{InMemoryAccount, InMemoryBackend, InMemoryEnvironment, InMemoryLayer};
+use crate::in_memory::{InMemoryAccount, InMemoryBackend, InMemoryEnvironment};
 use crate::types::{Fork, TestCompletionStatus, TestData, TestExpectException, TestMulti};
+use evm::backend::OverlayedBackend;
 use evm::standard::{Config, Etable, EtableResolver, Invoker, TransactArgs};
 use evm::utils::u256_to_h256;
 use evm::Capture;
@@ -136,7 +137,6 @@ pub fn run_test(
 					balance: account.balance,
 					code: account.code.0,
 					nonce: account.nonce,
-					original_storage: storage.clone(),
 					storage,
 				},
 			)
@@ -164,26 +164,27 @@ pub fn run_test(
 			.collect(),
 	};
 
-	let mut run_backend = InMemoryBackend {
+	let initial_accessed = {
+		let mut hots = BTreeSet::new();
+		for i in 1..10 {
+			hots.insert((u256_to_h256(U256::from(i)).into(), None));
+		}
+		hots
+	};
+
+	let base_backend = InMemoryBackend {
 		environment: env,
-		layers: vec![InMemoryLayer {
-			state,
-			logs: Vec::new(),
-			suicides: Vec::new(),
-			hots: {
-				let mut hots = BTreeSet::new();
-				for i in 1..10 {
-					hots.insert((u256_to_h256(U256::from(i)).into(), None));
-				}
-				hots
-			},
-		}],
+		state,
 	};
-	let mut step_backend = run_backend.clone();
+
+	let mut run_backend = OverlayedBackend::new(&base_backend, initial_accessed.clone());
+	let mut step_backend = OverlayedBackend::new(&base_backend, initial_accessed.clone());
 
 	// Run
 	let run_result = evm::transact(args.clone(), Some(4), &mut run_backend, &invoker);
-	run_backend.layers[0].clear_pending();
+	let run_changeset = run_backend.deconstruct().1;
+	let mut run_backend = base_backend.clone();
+	run_backend.apply_overlayed(&run_changeset);
 
 	// Step
 	if debug {
@@ -204,7 +205,9 @@ pub fn run_test(
 				}
 			},
 		);
-		step_backend.layers[0].clear_pending();
+		let step_changeset = step_backend.deconstruct().1;
+		let mut step_backend = base_backend.clone();
+		step_backend.apply_overlayed(&step_changeset);
 	}
 
 	let state_root = crate::hash::state_root(&run_backend);
@@ -219,7 +222,7 @@ pub fn run_test(
 
 	if state_root != test.post.hash {
 		if debug {
-			for (address, account) in &run_backend.layers[0].state {
+			for (address, account) in &run_backend.state {
 				println!(
 					"address: {:?}, balance: {}, nonce: {}, code: 0x{}, storage: {:?}",
 					address,

rust-toolchain.toml

@@ -1,4 +1,4 @@
 [toolchain]
-channel = "nightly"
+channel = "1.75.0"
 profile = "minimal"
 components = [ "rustfmt", "clippy" ]

src/backend/mod.rs

@@ -11,6 +11,9 @@
 //! pushing/poping layers are dealt by extern functions), layers are handled
 //! internally inside a backend.
 
+mod overlayed;
+
+pub use self::overlayed::{OverlayedBackend, OverlayedChangeSet};
 pub use evm_interpreter::{RuntimeBackend, RuntimeBaseBackend, RuntimeEnvironment};
 
 /// Backend with layers that can transactionally be committed or discarded.