Canonical state cache (master) (#2311)

* State cache

* Reduced copying data between caches

Whitespace and optional symbols

* Reduced copying data between caches

Whitespace and optional symbols

* Set a limit on storage cache

* Style and docs

ethcore/Cargo.toml

@@ -37,6 +37,7 @@ ethkey = { path = "../ethkey" }
 ethcore-ipc-nano = { path = "../ipc/nano" }
 rlp = { path = "../util/rlp" }
 rand = "0.3"
+lru-cache = "0.0.7"
 
 [dependencies.hyper]
 git = "https://github.com/ethcore/hyper"

ethcore/src/block.rs

@@ -19,6 +19,7 @@
 use common::*;
 use engines::Engine;
 use state::*;
+use state_db::StateDB;
 use verification::PreverifiedBlock;
 use trace::FlatTrace;
 use factory::Factories;
@@ -179,7 +180,7 @@ pub trait IsBlock {
 /// Trait for a object that has a state database.
 pub trait Drain {
 	/// Drop this object and return the underlieing database.
-	fn drain(self) -> Box<JournalDB>;
+	fn drain(self) -> StateDB;
 }
 
 impl IsBlock for ExecutedBlock {
@@ -231,7 +232,7 @@ impl<'x> OpenBlock<'x> {
 		engine: &'x Engine,
 		factories: Factories,
 		tracing: bool,
-		db: Box<JournalDB>,
+		db: StateDB,
 		parent: &Header,
 		last_hashes: Arc<LastHashes>,
 		author: Address,
@@ -474,7 +475,9 @@ impl LockedBlock {
 
 impl Drain for LockedBlock {
 	/// Drop this object and return the underlieing database.
-	fn drain(self) -> Box<JournalDB> { self.block.state.drop().1 }
+	fn drain(self) -> StateDB {
+		self.block.state.drop().1
+	}
 }
 
 impl SealedBlock {
@@ -490,7 +493,9 @@ impl SealedBlock {
 
 impl Drain for SealedBlock {
 	/// Drop this object and return the underlieing database.
-	fn drain(self) -> Box<JournalDB> { self.block.state.drop().1 }
+	fn drain(self) -> StateDB {
+		self.block.state.drop().1
+	}
 }
 
 impl IsBlock for SealedBlock {
@@ -505,7 +510,7 @@ pub fn enact(
 	uncles: &[Header],
 	engine: &Engine,
 	tracing: bool,
-	db: Box<JournalDB>,
+	db: StateDB,
 	parent: &Header,
 	last_hashes: Arc<LastHashes>,
 	factories: Factories,
@@ -537,7 +542,7 @@ pub fn enact_bytes(
 	block_bytes: &[u8],
 	engine: &Engine,
 	tracing: bool,
-	db: Box<JournalDB>,
+	db: StateDB,
 	parent: &Header,
 	last_hashes: Arc<LastHashes>,
 	factories: Factories,
@@ -553,7 +558,7 @@ pub fn enact_verified(
 	block: &PreverifiedBlock,
 	engine: &Engine,
 	tracing: bool,
-	db: Box<JournalDB>,
+	db: StateDB,
 	parent: &Header,
 	last_hashes: Arc<LastHashes>,
 	factories: Factories,
@@ -568,7 +573,7 @@ pub fn enact_and_seal(
 	block_bytes: &[u8],
 	engine: &Engine,
 	tracing: bool,
-	db: Box<JournalDB>,
+	db: StateDB,
 	parent: &Header,
 	last_hashes: Arc<LastHashes>,
 	factories: Factories,
@@ -588,9 +593,9 @@ mod tests {
 		use spec::*;
 		let spec = Spec::new_test();
 		let genesis_header = spec.genesis_header();
-		let mut db_result = get_temp_journal_db();
+		let mut db_result = get_temp_state_db();
 		let mut db = db_result.take();
-		spec.ensure_db_good(db.as_hashdb_mut()).unwrap();
+		spec.ensure_db_good(&mut db).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(&*spec.engine, Default::default(), false, db, &genesis_header, last_hashes, Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b = b.close_and_lock();
@@ -604,25 +609,25 @@ mod tests {
 		let engine = &*spec.engine;
 		let genesis_header = spec.genesis_header();
 
-		let mut db_result = get_temp_journal_db();
+		let mut db_result = get_temp_state_db();
 		let mut db = db_result.take();
-		spec.ensure_db_good(db.as_hashdb_mut()).unwrap();
+		spec.ensure_db_good(&mut db).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes.clone(), Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap()
 			.close_and_lock().seal(engine, vec![]).unwrap();
 		let orig_bytes = b.rlp_bytes();
 		let orig_db = b.drain();
 
-		let mut db_result = get_temp_journal_db();
+		let mut db_result = get_temp_state_db();
 		let mut db = db_result.take();
-		spec.ensure_db_good(db.as_hashdb_mut()).unwrap();
+		spec.ensure_db_good(&mut db).unwrap();
 		let e = enact_and_seal(&orig_bytes, engine, false, db, &genesis_header, last_hashes, Default::default()).unwrap();
 
 		assert_eq!(e.rlp_bytes(), orig_bytes);
 
 		let db = e.drain();
-		assert_eq!(orig_db.keys(), db.keys());
-		assert!(orig_db.keys().iter().filter(|k| orig_db.get(k.0) != db.get(k.0)).next() == None);
+		assert_eq!(orig_db.journal_db().keys(), db.journal_db().keys());
+		assert!(orig_db.journal_db().keys().iter().filter(|k| orig_db.journal_db().get(k.0) != db.journal_db().get(k.0)).next() == None);
 	}
 
 	#[test]
@@ -632,9 +637,9 @@ mod tests {
 		let engine = &*spec.engine;
 		let genesis_header = spec.genesis_header();
 
-		let mut db_result = get_temp_journal_db();
+		let mut db_result = get_temp_state_db();
 		let mut db = db_result.take();
-		spec.ensure_db_good(db.as_hashdb_mut()).unwrap();
+		spec.ensure_db_good(&mut db).unwrap();
 		let last_hashes = Arc::new(vec![genesis_header.hash()]);
 		let mut open_block = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes.clone(), Address::zero(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let mut uncle1_header = Header::new();
@@ -648,9 +653,9 @@ mod tests {
 		let orig_bytes = b.rlp_bytes();
 		let orig_db = b.drain();
 
-		let mut db_result = get_temp_journal_db();
+		let mut db_result = get_temp_state_db();
 		let mut db = db_result.take();
-		spec.ensure_db_good(db.as_hashdb_mut()).unwrap();
+		spec.ensure_db_good(&mut db).unwrap();
 		let e = enact_and_seal(&orig_bytes, engine, false, db, &genesis_header, last_hashes, Default::default()).unwrap();
 
 		let bytes = e.rlp_bytes();
@@ -659,7 +664,7 @@ mod tests {
 		assert_eq!(uncles[1].extra_data(), b"uncle2");
 
 		let db = e.drain();
-		assert_eq!(orig_db.keys(), db.keys());
-		assert!(orig_db.keys().iter().filter(|k| orig_db.get(k.0) != db.get(k.0)).next() == None);
+		assert_eq!(orig_db.journal_db().keys(), db.journal_db().keys());
+		assert!(orig_db.journal_db().keys().iter().filter(|k| orig_db.journal_db().get(k.0) != db.journal_db().get(k.0)).next() == None);
 	}
 }

ethcore/src/client/client.rs

@@ -23,7 +23,7 @@ use time::precise_time_ns;
 
 // util
 use util::{Bytes, PerfTimer, Itertools, Mutex, RwLock};
-use util::journaldb::{self, JournalDB};
+use util::journaldb;
 use util::{U256, H256, Address, H2048, Uint};
 use util::TrieFactory;
 use util::kvdb::*;
@@ -65,7 +65,7 @@ use miner::{Miner, MinerService};
 use snapshot::{self, io as snapshot_io};
 use factory::Factories;
 use rlp::{View, UntrustedRlp};
-
+use state_db::StateDB;
 
 // re-export
 pub use types::blockchain_info::BlockChainInfo;
@@ -125,9 +125,9 @@ pub struct Client {
 	tracedb: RwLock<TraceDB<BlockChain>>,
 	engine: Arc<Engine>,
 	config: ClientConfig,
-	db: RwLock<Arc<Database>>,
 	pruning: journaldb::Algorithm,
-	state_db: RwLock<Box<JournalDB>>,
+	db: RwLock<Arc<Database>>,
+	state_db: Mutex<StateDB>,
 	block_queue: BlockQueue,
 	report: RwLock<ClientReport>,
 	import_lock: Mutex<()>,
@@ -171,14 +171,15 @@ impl Client {
 		let chain = Arc::new(BlockChain::new(config.blockchain.clone(), &gb, db.clone()));
 		let tracedb = RwLock::new(TraceDB::new(config.tracing.clone(), db.clone(), chain.clone()));
 
-		let mut state_db = journaldb::new(db.clone(), config.pruning, ::db::COL_STATE);
-		if state_db.is_empty() && try!(spec.ensure_db_good(state_db.as_hashdb_mut())) {
+		let journal_db = journaldb::new(db.clone(), config.pruning, ::db::COL_STATE);
+		let mut state_db = StateDB::new(journal_db);
+		if state_db.journal_db().is_empty() && try!(spec.ensure_db_good(&mut state_db)) {
 			let mut batch = DBTransaction::new(&db);
 			try!(state_db.commit(&mut batch, 0, &spec.genesis_header().hash(), None));
 			try!(db.write(batch).map_err(ClientError::Database));
 		}
 
-		if !chain.block_header(&chain.best_block_hash()).map_or(true, |h| state_db.contains(h.state_root())) {
+		if !chain.block_header(&chain.best_block_hash()).map_or(true, |h| state_db.journal_db().contains(h.state_root())) {
 			warn!("State root not found for block #{} ({})", chain.best_block_number(), chain.best_block_hash().hex());
 		}
 
@@ -207,7 +208,7 @@ impl Client {
 			verifier: verification::new(config.verifier_type.clone()),
 			config: config,
 			db: RwLock::new(db),
-			state_db: RwLock::new(state_db),
+			state_db: Mutex::new(state_db),
 			block_queue: block_queue,
 			report: RwLock::new(Default::default()),
 			import_lock: Mutex::new(()),
@@ -298,7 +299,8 @@ impl Client {
 		// Enact Verified Block
 		let parent = chain_has_parent.unwrap();
 		let last_hashes = self.build_last_hashes(header.parent_hash().clone());
-		let db = self.state_db.read().boxed_clone();
+		let is_canon = header.parent_hash() == &chain.best_block_hash();
+		let db = if is_canon { self.state_db.lock().boxed_clone_canon() } else { self.state_db.lock().boxed_clone() };
 
 		let enact_result = enact_verified(block, engine, self.tracedb.read().tracing_enabled(), db, &parent, last_hashes, self.factories.clone());
 		if let Err(e) = enact_result {
@@ -441,7 +443,8 @@ impl Client {
 		// CHECK! I *think* this is fine, even if the state_root is equal to another
 		// already-imported block of the same number.
 		// TODO: Prove it with a test.
-		block.drain().commit(&mut batch, number, hash, ancient).expect("DB commit failed.");
+		let mut state = block.drain();
+		state.commit(&mut batch, number, hash, ancient).expect("DB commit failed.");
 
 		let route = chain.insert_block(&mut batch, block_data, receipts);
 		self.tracedb.read().import(&mut batch, TraceImportRequest {
@@ -454,7 +457,6 @@ impl Client {
 		// Final commit to the DB
 		self.db.read().write_buffered(batch);
 		chain.commit();
-
 		self.update_last_hashes(&parent, hash);
 		route
 	}
@@ -496,7 +498,7 @@ impl Client {
 		};
 
 		self.block_header(id).and_then(|header| {
-			let db = self.state_db.read().boxed_clone();
+			let db = self.state_db.lock().boxed_clone();
 
 			// early exit for pruned blocks
 			if db.is_pruned() && self.chain.read().best_block_number() >= block_number + HISTORY {
@@ -527,7 +529,7 @@ impl Client {
 	/// Get a copy of the best block's state.
 	pub fn state(&self) -> State {
 		State::from_existing(
-			self.state_db.read().boxed_clone(),
+			self.state_db.lock().boxed_clone(),
 			HeaderView::new(&self.best_block_header()).state_root(),
 			self.engine.account_start_nonce(),
 			self.factories.clone())
@@ -542,7 +544,7 @@ impl Client {
 	/// Get the report.
 	pub fn report(&self) -> ClientReport {
 		let mut report = self.report.read().clone();
-		report.state_db_mem = self.state_db.read().mem_used();
+		report.state_db_mem = self.state_db.lock().mem_used();
 		report
 	}
 
@@ -598,7 +600,7 @@ impl Client {
 	/// Take a snapshot at the given block.
 	/// If the ID given is "latest", this will default to 1000 blocks behind.
 	pub fn take_snapshot<W: snapshot_io::SnapshotWriter + Send>(&self, writer: W, at: BlockID, p: &snapshot::Progress) -> Result<(), EthcoreError> {
-		let db = self.state_db.read().boxed_clone();
+		let db = self.state_db.lock().journal_db().boxed_clone();
 		let best_block_number = self.chain_info().best_block_number;
 		let block_number = try!(self.block_number(at).ok_or(snapshot::Error::InvalidStartingBlock(at)));
 
@@ -677,14 +679,14 @@ impl snapshot::DatabaseRestore for Client {
 		trace!(target: "snapshot", "Replacing client database with {:?}", new_db);
 
 		let _import_lock = self.import_lock.lock();
-		let mut state_db = self.state_db.write();
+		let mut state_db = self.state_db.lock();
 		let mut chain = self.chain.write();
 		let mut tracedb = self.tracedb.write();
 		self.miner.clear();
 		let db = self.db.write();
 		try!(db.restore(new_db));
 
-		*state_db = journaldb::new(db.clone(), self.pruning, ::db::COL_STATE);
+		*state_db = StateDB::new(journaldb::new(db.clone(), self.pruning, ::db::COL_STATE));
 		*chain = Arc::new(BlockChain::new(self.config.blockchain.clone(), &[], db.clone()));
 		*tracedb = TraceDB::new(self.config.tracing.clone(), db.clone(), chain.clone());
 		Ok(())
@@ -908,7 +910,7 @@ impl BlockChainClient for Client {
 	}
 
 	fn state_data(&self, hash: &H256) -> Option<Bytes> {
-		self.state_db.read().state(hash)
+		self.state_db.lock().journal_db().state(hash)
 	}
 
 	fn block_receipts(&self, hash: &H256) -> Option<Bytes> {
@@ -1050,7 +1052,7 @@ impl MiningBlockChainClient for Client {
 			engine,
 			self.factories.clone(),
 			false,	// TODO: this will need to be parameterised once we want to do immediate mining insertion.
-			self.state_db.read().boxed_clone(),
+			self.state_db.lock().boxed_clone(),
 			&chain.block_header(&h).expect("h is best block hash: so its header must exist: qed"),
 			self.build_last_hashes(h.clone()),
 			author,

ethcore/src/client/test_client.rs

@@ -42,6 +42,7 @@ use block::{OpenBlock, SealedBlock};
 use executive::Executed;
 use error::CallError;
 use trace::LocalizedTrace;
+use state_db::StateDB;
 
 /// Test client.
 pub struct TestBlockChainClient {
@@ -283,23 +284,24 @@ impl TestBlockChainClient {
 	}
 }
 
-pub fn get_temp_journal_db() -> GuardedTempResult<Box<JournalDB>> {
+pub fn get_temp_state_db() -> GuardedTempResult<StateDB> {
 	let temp = RandomTempPath::new();
 	let db = Database::open_default(temp.as_str()).unwrap();
 	let journal_db = journaldb::new(Arc::new(db), journaldb::Algorithm::EarlyMerge, None);
+	let state_db = StateDB::new(journal_db);
 	GuardedTempResult {
 		_temp: temp,
-		result: Some(journal_db)
+		result: Some(state_db)
 	}
 }
 
 impl MiningBlockChainClient for TestBlockChainClient {
 	fn prepare_open_block(&self, author: Address, gas_range_target: (U256, U256), extra_data: Bytes) -> OpenBlock {
 		let engine = &*self.spec.engine;
 		let genesis_header = self.spec.genesis_header();
-		let mut db_result = get_temp_journal_db();
+		let mut db_result = get_temp_state_db();
 		let mut db = db_result.take();
-		self.spec.ensure_db_good(db.as_hashdb_mut()).unwrap();
+		self.spec.ensure_db_good(&mut db).unwrap();
 
 		let last_hashes = vec![genesis_header.hash()];
 		let mut open_block = OpenBlock::new(