Merge pull request #581 from ethcore/verifier_trait

verifier trait

ethcore/src/client.rs

@@ -16,6 +16,7 @@
 
 //! Blockchain database client.
 
+use std::marker::PhantomData;
 use util::*;
 use util::panics::*;
 use blockchain::{BlockChain, BlockProvider};
@@ -188,7 +189,7 @@ impl ClientReport {
 
 /// Blockchain database client backed by a persistent database. Owns and manages a blockchain and a block queue.
 /// Call `import_block()` to import a block asynchronously; `flush_queue()` flushes the queue.
-pub struct Client {
+pub struct Client<V = CanonVerifier> where V: Verifier {
 	chain: Arc<RwLock<BlockChain>>,
 	engine: Arc<Box<Engine>>,
 	state_db: Mutex<JournalDB>,
@@ -201,14 +202,22 @@ pub struct Client {
 	sealing_block: Mutex<Option<ClosedBlock>>,
 	author: RwLock<Address>,
 	extra_data: RwLock<Bytes>,
+	verifier: PhantomData<V>
 }
 
 const HISTORY: u64 = 1000;
 const CLIENT_DB_VER_STR: &'static str = "4.0";
 
-impl Client {
+impl Client<CanonVerifier> {
 	/// Create a new client with given spec and DB path.
 	pub fn new(config: ClientConfig, spec: Spec, path: &Path, message_channel: IoChannel<NetSyncMessage> ) -> Result<Arc<Client>, Error> {
+		Client::<CanonVerifier>::new_with_verifier(config, spec, path, message_channel)
+	}
+}
+
+impl<V> Client<V> where V: Verifier {
+	///  Create a new client with given spec and DB path and custom verifier.
+	pub fn new_with_verifier(config: ClientConfig, spec: Spec, path: &Path, message_channel: IoChannel<NetSyncMessage> ) -> Result<Arc<Client>, Error> {
 		let mut dir = path.to_path_buf();
 		dir.push(H64::from(spec.genesis_header().hash()).hex());
 		//TODO: sec/fat: pruned/full versioning
@@ -240,6 +249,7 @@ impl Client {
 			sealing_block: Mutex::new(None),
 			author: RwLock::new(Address::new()),
 			extra_data: RwLock::new(Vec::new()),
+			verifier: PhantomData
 		}))
 	}
 
@@ -302,7 +312,7 @@ impl Client {
 
 		// Final Verification
 		let closed_block = enact_result.unwrap();
-		if let Err(e) = verify_block_final(&header, closed_block.block().header()) {
+		if let Err(e) = V::verify_block_final(&header, closed_block.block().header()) {
 			warn!(target: "client", "Stage 4 block verification failed for #{} ({})\nError: {:?}", header.number(), header.hash(), e);
 			return Err(());
 		}
@@ -503,7 +513,7 @@ impl Client {
 
 // TODO: need MinerService MinerIoHandler
 
-impl BlockChainClient for Client {
+impl<V> BlockChainClient for Client<V> where V: Verifier {
 	fn block_header(&self, id: BlockId) -> Option<Bytes> {
 		let chain = self.chain.read().unwrap();
 		Self::block_hash(&chain, id).and_then(|hash| chain.block(&hash).map(|bytes| BlockView::new(&bytes).rlp().at(0).as_raw().to_vec()))

ethcore/src/verification/canon_verifier.rs

@@ -0,0 +1,28 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use error::Error;
+use header::Header;
+use super::Verifier;
+use super::verification;
+
+pub struct CanonVerifier;
+
+impl Verifier for CanonVerifier {
+	fn verify_block_final(expected: &Header, got: &Header) -> Result<(), Error> {
+		verification::verify_block_final(expected, got)
+	}
+}

ethcore/src/verification/mod.rs

@@ -0,0 +1,25 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+pub mod verification;
+pub mod verifier;
+mod canon_verifier;
+mod noop_verifier;
+
+pub use self::verification::*;
+pub use self::verifier::Verifier;
+pub use self::canon_verifier::CanonVerifier;
+pub use self::noop_verifier::NoopVerifier;

ethcore/src/verification/noop_verifier.rs

@@ -0,0 +1,27 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use error::Error;
+use header::Header;
+use super::Verifier;
+
+pub struct NoopVerifier;
+
+impl Verifier for NoopVerifier {
+	fn verify_block_final(_expected: &Header, _got: &Header) -> Result<(), Error> {
+		Ok(())
+	}
+}

ethcore/src/verification/verifier.rs

@@ -0,0 +1,23 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use error::Error;
+use header::Header;
+
+/// Should be used to verify blocks.
+pub trait Verifier: Send + Sync {
+	fn verify_block_final(expected: &Header, got: &Header) -> Result<(), Error>;
+}