Merge branch 'master' of github.com:ethcore/parity into jdb_option2

util/src/hash.rs

@@ -257,7 +257,7 @@ macro_rules! impl_hash {
 							return Err(serde::Error::custom("Invalid length."));
 						}
 
-						value[2..].from_hex().map(|ref v| $from::from_slice(v)).map_err(|_| serde::Error::custom("Invalid valid hex."))
+						value[2..].from_hex().map(|ref v| $from::from_slice(v)).map_err(|_| serde::Error::custom("Invalid hex value."))
 					}
 
 					fn visit_string<E>(&mut self, value: String) -> Result<Self::Value, E> where E: serde::Error {
@@ -305,7 +305,7 @@ macro_rules! impl_hash {
 		}
 
 		impl Copy for $from {}
-		#[cfg_attr(all(nightly, feature="dev"), allow(expl_impl_clone_on_copy))]
+		#[cfg_attr(feature="dev", allow(expl_impl_clone_on_copy))]
 		impl Clone for $from {
 			fn clone(&self) -> $from {
 				unsafe {
@@ -637,7 +637,7 @@ mod tests {
 	use std::str::FromStr;
 
 	#[test]
-	#[cfg_attr(all(nightly, feature="dev"), allow(eq_op))]
+	#[cfg_attr(feature="dev", allow(eq_op))]
 	fn hash() {
 		let h = H64([0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef]);
 		assert_eq!(H64::from_str("0123456789abcdef").unwrap(), h);

util/src/hashdb.rs

@@ -20,7 +20,7 @@ use bytes::*;
 use std::collections::HashMap;
 
 /// Trait modelling datastore keyed by a 32-byte Keccak hash.
-pub trait HashDB {
+pub trait HashDB : AsHashDB {
 	/// Get the keys in the database together with number of underlying references.
 	fn keys(&self) -> HashMap<H256, i32>;
 
@@ -111,3 +111,16 @@ pub trait HashDB {
 	/// ```
 	fn remove(&mut self, key: &H256) { self.kill(key) }
 }
+
+/// Upcast trait.
+pub trait AsHashDB {
+	/// Perform upcast to HashDB for anything that derives from HashDB.
+	fn as_hashdb(&self) -> &HashDB;
+	/// Perform mutable upcast to HashDB for anything that derives from HashDB.
+	fn as_hashdb_mut(&mut self) -> &mut HashDB;
+}
+
+impl<T: HashDB> AsHashDB for T {
+	fn as_hashdb(&self) -> &HashDB { self }
+	fn as_hashdb_mut(&mut self) -> &mut HashDB { self }
+}

util/src/journaldb/archivedb.rs

@@ -0,0 +1,388 @@
+// 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/>.
+
+//! Disk-backed HashDB implementation.
+
+use common::*;
+use rlp::*;
+use hashdb::*;
+use memorydb::*;
+use super::traits::JournalDB;
+use kvdb::{Database, DBTransaction, DatabaseConfig};
+#[cfg(test)]
+use std::env;
+
+/// Implementation of the HashDB trait for a disk-backed database with a memory overlay
+/// and latent-removal semantics.
+///
+/// Like OverlayDB, there is a memory overlay; `commit()` must be called in order to
+/// write operations out to disk. Unlike OverlayDB, `remove()` operations do not take effect
+/// immediately. Rather some age (based on a linear but arbitrary metric) must pass before
+/// the removals actually take effect.
+pub struct ArchiveDB {
+	overlay: MemoryDB,
+	backing: Arc<Database>,
+}
+
+// all keys must be at least 12 bytes
+const LATEST_ERA_KEY : [u8; 12] = [ b'l', b'a', b's', b't', 0, 0, 0, 0, 0, 0, 0, 0 ];
+const VERSION_KEY : [u8; 12] = [ b'j', b'v', b'e', b'r', 0, 0, 0, 0, 0, 0, 0, 0 ];
+const DB_VERSION : u32 = 259;
+
+impl ArchiveDB {
+	/// Create a new instance from file
+	pub fn new(path: &str) -> ArchiveDB {
+		let opts = DatabaseConfig {
+			prefix_size: Some(12) //use 12 bytes as prefix, this must match account_db prefix
+		};
+		let backing = Database::open(&opts, path).unwrap_or_else(|e| {
+			panic!("Error opening state db: {}", e);
+		});
+		if !backing.is_empty() {
+			match backing.get(&VERSION_KEY).map(|d| d.map(|v| decode::<u32>(&v))) {
+				Ok(Some(DB_VERSION)) => {},
+				v => panic!("Incompatible DB version, expected {}, got {:?}", DB_VERSION, v)
+			}
+		} else {
+			backing.put(&VERSION_KEY, &encode(&DB_VERSION)).expect("Error writing version to database");
+		}
+
+		ArchiveDB {
+			overlay: MemoryDB::new(),
+			backing: Arc::new(backing),
+		}
+	}
+
+	/// Create a new instance with an anonymous temporary database.
+	#[cfg(test)]
+	fn new_temp() -> ArchiveDB {
+		let mut dir = env::temp_dir();
+		dir.push(H32::random().hex());
+		Self::new(dir.to_str().unwrap())
+	}
+
+	fn payload(&self, key: &H256) -> Option<Bytes> {
+		self.backing.get(&key.bytes()).expect("Low-level database error. Some issue with your hard disk?").map(|v| v.to_vec())
+	}
+}
+
+impl HashDB for ArchiveDB {
+	fn keys(&self) -> HashMap<H256, i32> {
+		let mut ret: HashMap<H256, i32> = HashMap::new();
+		for (key, _) in self.backing.iter() {
+			let h = H256::from_slice(key.deref());
+			ret.insert(h, 1);
+		}
+
+		for (key, refs) in self.overlay.keys().into_iter() {
+			let refs = *ret.get(&key).unwrap_or(&0) + refs;
+			ret.insert(key, refs);
+		}
+		ret
+	}
+
+	fn lookup(&self, key: &H256) -> Option<&[u8]> {
+		let k = self.overlay.raw(key);
+		match k {
+			Some(&(ref d, rc)) if rc > 0 => Some(d),
+			_ => {
+				if let Some(x) = self.payload(key) {
+					Some(&self.overlay.denote(key, x).0)
+				}
+				else {
+					None
+				}
+			}
+		}
+	}
+
+	fn exists(&self, key: &H256) -> bool {
+		self.lookup(key).is_some()
+	}
+
+	fn insert(&mut self, value: &[u8]) -> H256 {
+		self.overlay.insert(value)
+	}
+	fn emplace(&mut self, key: H256, value: Bytes) {
+		self.overlay.emplace(key, value);
+	}
+	fn kill(&mut self, key: &H256) {
+		self.overlay.kill(key);
+	}
+}
+
+impl JournalDB for ArchiveDB {
+	fn spawn(&self) -> Box<JournalDB> {
+		Box::new(ArchiveDB {
+			overlay: MemoryDB::new(),
+			backing: self.backing.clone(),
+		})
+	}
+
+	fn mem_used(&self) -> usize {
+		self.overlay.mem_used()
+ 	}
+
+	fn is_empty(&self) -> bool {
+		self.backing.get(&LATEST_ERA_KEY).expect("Low level database error").is_none()
+	}
+
+	fn commit(&mut self, _: u64, _: &H256, _: Option<(u64, H256)>) -> Result<u32, UtilError> {
+		let batch = DBTransaction::new();
+		let mut inserts = 0usize;
+		let mut deletes = 0usize;
+		for i in self.overlay.drain().into_iter() {
+			let (key, (value, rc)) = i;
+			if rc > 0 {
+				assert!(rc == 1);
+				batch.put(&key.bytes(), &value).expect("Low-level database error. Some issue with your hard disk?");
+				inserts += 1;
+			}
+			if rc < 0 {
+				assert!(rc == -1);
+				deletes += 1;
+			}
+		}
+		try!(self.backing.write(batch));
+		Ok((inserts + deletes) as u32)
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use common::*;
+	use super::*;
+	use hashdb::*;
+	use journaldb::traits::JournalDB;
+
+	#[test]
+	fn insert_same_in_fork() {
+		// history is 1
+		let mut jdb = ArchiveDB::new_temp();
+
+		let x = jdb.insert(b"X");
+		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		jdb.commit(3, &b"1002a".sha3(), Some((1, b"1".sha3()))).unwrap();
+		jdb.commit(4, &b"1003a".sha3(), Some((2, b"2".sha3()))).unwrap();
+
+		jdb.remove(&x);
+		jdb.commit(3, &b"1002b".sha3(), Some((1, b"1".sha3()))).unwrap();
+		let x = jdb.insert(b"X");
+		jdb.commit(4, &b"1003b".sha3(), Some((2, b"2".sha3()))).unwrap();
+
+		jdb.commit(5, &b"1004a".sha3(), Some((3, b"1002a".sha3()))).unwrap();
+		jdb.commit(6, &b"1005a".sha3(), Some((4, b"1003a".sha3()))).unwrap();
+
+		assert!(jdb.exists(&x));
+	}
+
+	#[test]
+	fn long_history() {
+		// history is 3
+		let mut jdb = ArchiveDB::new_temp();
+		let h = jdb.insert(b"foo");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.remove(&h);
+		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.commit(3, &b"3".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.commit(4, &b"4".sha3(), Some((1, b"1".sha3()))).unwrap();
+	}
+
+	#[test]
+	fn complex() {
+		// history is 1
+		let mut jdb = ArchiveDB::new_temp();
+
+		let foo = jdb.insert(b"foo");
+		let bar = jdb.insert(b"bar");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+
+		jdb.remove(&foo);
+		jdb.remove(&bar);
+		let baz = jdb.insert(b"baz");
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+		assert!(jdb.exists(&baz));
+
+		let foo = jdb.insert(b"foo");
+		jdb.remove(&baz);
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&baz));
+
+		jdb.remove(&foo);
+		jdb.commit(3, &b"3".sha3(), Some((2, b"2".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+
+		jdb.commit(4, &b"4".sha3(), Some((3, b"3".sha3()))).unwrap();
+	}
+
+	#[test]
+	fn fork() {
+		// history is 1
+		let mut jdb = ArchiveDB::new_temp();
+
+		let foo = jdb.insert(b"foo");
+		let bar = jdb.insert(b"bar");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+
+		jdb.remove(&foo);
+		let baz = jdb.insert(b"baz");
+		jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+		jdb.remove(&bar);
+		jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+		assert!(jdb.exists(&baz));
+
+		jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+	}
+
+	#[test]
+	fn overwrite() {
+		// history is 1
+		let mut jdb = ArchiveDB::new_temp();
+
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&foo));
+
+		jdb.remove(&foo);
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		jdb.insert(b"foo");
+		assert!(jdb.exists(&foo));
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		jdb.commit(3, &b"2".sha3(), Some((0, b"2".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+	}
+
+	#[test]
+	fn fork_same_key() {
+		// history is 1
+		let mut jdb = ArchiveDB::new_temp();
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+
+		let foo = jdb.insert(b"foo");
+		jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+		jdb.insert(b"foo");
+		jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+
+		jdb.commit(2, &b"2a".sha3(), Some((1, b"1a".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+	}
+
+
+	#[test]
+	fn reopen() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+		let bar = H256::random();
+
+		let foo = {
+			let mut jdb = ArchiveDB::new(dir.to_str().unwrap());
+			// history is 1
+			let foo = jdb.insert(b"foo");
+			jdb.emplace(bar.clone(), b"bar".to_vec());
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			foo
+		};
+
+		{
+			let mut jdb = ArchiveDB::new(dir.to_str().unwrap());
+			jdb.remove(&foo);
+			jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		}
+
+		{
+			let mut jdb = ArchiveDB::new(dir.to_str().unwrap());
+			assert!(jdb.exists(&foo));
+			assert!(jdb.exists(&bar));
+			jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		}
+	}
+
+	#[test]
+	fn reopen_remove() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let foo = {
+			let mut jdb = ArchiveDB::new(dir.to_str().unwrap());
+			// history is 1
+			let foo = jdb.insert(b"foo");
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+			// foo is ancient history.
+
+			jdb.insert(b"foo");
+			jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+			foo
+		};
+
+		{
+			let mut jdb = ArchiveDB::new(dir.to_str().unwrap());
+			jdb.remove(&foo);
+			jdb.commit(3, &b"3".sha3(), Some((2, b"2".sha3()))).unwrap();
+			assert!(jdb.exists(&foo));
+			jdb.remove(&foo);
+			jdb.commit(4, &b"4".sha3(), Some((3, b"3".sha3()))).unwrap();
+			jdb.commit(5, &b"5".sha3(), Some((4, b"4".sha3()))).unwrap();
+		}
+	}
+	#[test]
+	fn reopen_fork() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+		let (foo, _, _) = {
+			let mut jdb = ArchiveDB::new(dir.to_str().unwrap());
+			// history is 1
+			let foo = jdb.insert(b"foo");
+			let bar = jdb.insert(b"bar");
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			jdb.remove(&foo);
+			let baz = jdb.insert(b"baz");
+			jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+			jdb.remove(&bar);
+			jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+			(foo, bar, baz)
+		};
+
+		{
+			let mut jdb = ArchiveDB::new(dir.to_str().unwrap());
+			jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
+			assert!(jdb.exists(&foo));
+		}
+	}
+}

util/src/journaldb/mod.rs

@@ -0,0 +1,80 @@
+// 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/>.
+
+//! JournalDB interface and implementation.
+
+use common::*;
+
+/// Export the journaldb module.
+pub mod traits;
+mod archivedb;
+mod optiononedb;
+mod overlay;
+
+/// Export the JournalDB trait.
+pub use self::traits::JournalDB;
+
+/// A journal database algorithm.
+#[derive(Debug)]
+pub enum Algorithm {
+	/// Keep all keys forever.
+	Archive,
+
+	/// Ancient and recent history maintained separately; recent history lasts for particular
+	/// number of blocks.
+	///
+	/// Inserts go into backing database, journal retains knowledge of whether backing DB key is
+	/// ancient or recent. Non-canon inserts get explicitly reverted and removed from backing DB.
+	EarlyMerge,
+
+	/// Ancient and recent history maintained separately; recent history lasts for particular
+	/// number of blocks.
+	///
+	/// Inserts go into memory overlay, which is tried for key fetches. Memory overlay gets
+	/// flushed in backing only at end of recent history.
+	OverlayRecent,
+
+	/// Ancient and recent history maintained separately; recent history lasts for particular
+	/// number of blocks.
+	///
+	/// References are counted in disk-backed DB.
+	RefCounted,
+}
+
+impl Default for Algorithm {
+	fn default() -> Algorithm { Algorithm::Archive }
+}
+
+impl fmt::Display for Algorithm {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		write!(f, "{}", match self {
+			&Algorithm::Archive => "archive",
+			&Algorithm::EarlyMerge => "earlymerge",
+			&Algorithm::OverlayRecent => "overlayrecent",
+			&Algorithm::RefCounted => "refcounted",
+		})
+	}
+}
+
+/// Create a new JournalDB trait object.
+pub fn new(path: &str, algorithm: Algorithm) -> Box<JournalDB> {
+	match algorithm {
+		Algorithm::Archive => Box::new(archivedb::ArchiveDB::new(path)),
+		Algorithm::EarlyMerge => Box::new(optiononedb::OptionOneDB::new(path)),
+		Algorithm::OverlayRecent => Box::new(overlay::JournalOverlayDB::new(path)),
+		_ => unimplemented!(),
+	}
+}

util/src/journaldb/optiononedb.rs

@@ -0,0 +1,618 @@
+// 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/>.
+
+//! Disk-backed HashDB implementation.
+
+use common::*;
+use rlp::*;
+use hashdb::*;
+use memorydb::*;
+use super::traits::JournalDB;
+use kvdb::{Database, DBTransaction, DatabaseConfig};
+#[cfg(test)]
+use std::env;
+
+/// Implementation of the HashDB trait for a disk-backed database with a memory overlay
+/// and latent-removal semantics.
+///
+/// Like OverlayDB, there is a memory overlay; `commit()` must be called in order to
+/// write operations out to disk. Unlike OverlayDB, `remove()` operations do not take effect
+/// immediately. Rather some age (based on a linear but arbitrary metric) must pass before
+/// the removals actually take effect.
+pub struct OptionOneDB {
+	overlay: MemoryDB,
+	backing: Arc<Database>,
+	counters: Option<Arc<RwLock<HashMap<H256, i32>>>>,
+}
+
+// all keys must be at least 12 bytes
+const LATEST_ERA_KEY : [u8; 12] = [ b'l', b'a', b's', b't', 0, 0, 0, 0, 0, 0, 0, 0 ];
+const VERSION_KEY : [u8; 12] = [ b'j', b'v', b'e', b'r', 0, 0, 0, 0, 0, 0, 0, 0 ];
+const DB_VERSION : u32 = 3;
+const PADDING : [u8; 10] = [ 0u8; 10 ];
+
+impl OptionOneDB {
+	/// Create a new instance from file
+	pub fn new(path: &str) -> OptionOneDB {
+		let opts = DatabaseConfig {
+			prefix_size: Some(12) //use 12 bytes as prefix, this must match account_db prefix
+		};
+		let backing = Database::open(&opts, path).unwrap_or_else(|e| {
+			panic!("Error opening state db: {}", e);
+		});
+		if !backing.is_empty() {
+			match backing.get(&VERSION_KEY).map(|d| d.map(|v| decode::<u32>(&v))) {
+				Ok(Some(DB_VERSION)) => {},
+				v => panic!("Incompatible DB version, expected {}, got {:?}", DB_VERSION, v)
+			}
+		} else {
+			backing.put(&VERSION_KEY, &encode(&DB_VERSION)).expect("Error writing version to database");
+		}
+
+		let counters = Some(Arc::new(RwLock::new(OptionOneDB::read_counters(&backing))));
+		OptionOneDB {
+			overlay: MemoryDB::new(),
+			backing: Arc::new(backing),
+			counters: counters,
+		}
+	}
+
+	/// Create a new instance with an anonymous temporary database.
+	#[cfg(test)]
+	fn new_temp() -> OptionOneDB {
+		let mut dir = env::temp_dir();
+		dir.push(H32::random().hex());
+		Self::new(dir.to_str().unwrap())
+	}
+
+	fn morph_key(key: &H256, index: u8) -> Bytes {
+		let mut ret = key.bytes().to_owned();
+		ret.push(index);
+		ret
+	}
+
+	// The next three are valid only as long as there is an insert operation of `key` in the journal.
+	fn set_already_in(batch: &DBTransaction, key: &H256) { batch.put(&Self::morph_key(key, 0), &[1u8]).expect("Low-level database error. Some issue with your hard disk?"); }
+	fn reset_already_in(batch: &DBTransaction, key: &H256) { batch.delete(&Self::morph_key(key, 0)).expect("Low-level database error. Some issue with your hard disk?"); }
+	fn is_already_in(backing: &Database, key: &H256) -> bool {
+		backing.get(&Self::morph_key(key, 0)).expect("Low-level database error. Some issue with your hard disk?").is_some()
+	}
+
+	fn insert_keys(inserts: &[(H256, Bytes)], backing: &Database, counters: &mut HashMap<H256, i32>, batch: &DBTransaction) {
+		for &(ref h, ref d) in inserts {
+			if let Some(c) = counters.get_mut(h) {
+				// already counting. increment.
+				*c += 1;
+				continue;
+			}
+
+			// this is the first entry for this node in the journal.
+			if backing.get(&h.bytes()).expect("Low-level database error. Some issue with your hard disk?").is_some() {
+				// already in the backing DB. start counting, and remember it was already in.
+				Self::set_already_in(batch, &h);
+				counters.insert(h.clone(), 1);
+				continue;
+			}
+
+			// Gets removed when a key leaves the journal, so should never be set when we're placing a new key.
+			//Self::reset_already_in(&h);
+			assert!(!Self::is_already_in(backing, &h));
+			batch.put(&h.bytes(), d).expect("Low-level database error. Some issue with your hard disk?");
+		}
+	}
+
+	fn replay_keys(inserts: &[H256], backing: &Database, counters: &mut HashMap<H256, i32>) {
+		trace!("replay_keys: inserts={:?}, counters={:?}", inserts, counters);
+		for h in inserts {
+			if let Some(c) = counters.get_mut(h) {
+				// already counting. increment.
+				*c += 1;
+				continue;
+			}
+
+			// this is the first entry for this node in the journal.
+			// it is initialised to 1 if it was already in.
+			if Self::is_already_in(backing, h) {
+				trace!("replace_keys: Key {} was already in!", h);
+				counters.insert(h.clone(), 1);
+			}
+		}
+		trace!("replay_keys: (end) counters={:?}", counters);
+	}
+
+	fn kill_keys(deletes: Vec<H256>, counters: &mut HashMap<H256, i32>, batch: &DBTransaction) {
+		for h in deletes.into_iter() {
+			let mut n: Option<i32> = None;
+			if let Some(c) = counters.get_mut(&h) {
+				if *c > 1 {
+					*c -= 1;
+					continue;
+				} else {
+					n = Some(*c);
+				}
+			}
+			match n {
+				Some(i) if i == 1 => {
+					counters.remove(&h);
+					Self::reset_already_in(batch, &h);
+				}
+				None => {
+					// Gets removed when moving from 1 to 0 additional refs. Should never be here at 0 additional refs.
+					//assert!(!Self::is_already_in(db, &h));
+					batch.delete(&h.bytes()).expect("Low-level database error. Some issue with your hard disk?");
+				}
+				_ => panic!("Invalid value in counters: {:?}", n),
+			}
+		}
+	}
+
+	fn payload(&self, key: &H256) -> Option<Bytes> {
+		self.backing.get(&key.bytes()).expect("Low-level database error. Some issue with your hard disk?").map(|v| v.to_vec())
+	}
+
+	fn read_counters(db: &Database) -> HashMap<H256, i32> {
+		let mut counters = HashMap::new();
+		if let Some(val) = db.get(&LATEST_ERA_KEY).expect("Low-level database error.") {
+			let mut era = decode::<u64>(&val);
+			loop {
+				let mut index = 0usize;
+				while let Some(rlp_data) = db.get({
+					let mut r = RlpStream::new_list(3);
+					r.append(&era);
+					r.append(&index);
+					r.append(&&PADDING[..]);
+					&r.drain()
+				}).expect("Low-level database error.") {
+					trace!("read_counters: era={}, index={}", era, index);
+					let rlp = Rlp::new(&rlp_data);
+					let inserts: Vec<H256> = rlp.val_at(1);
+					Self::replay_keys(&inserts, db, &mut counters);
+					index += 1;
+				};
+				if index == 0 || era == 0 {
+					break;
+				}
+				era -= 1;
+			}
+		}
+		trace!("Recovered {} counters", counters.len());
+		counters
+	}
+}
+
+impl HashDB for OptionOneDB {
+	fn keys(&self) -> HashMap<H256, i32> {
+		let mut ret: HashMap<H256, i32> = HashMap::new();
+		for (key, _) in self.backing.iter() {
+			let h = H256::from_slice(key.deref());
+			ret.insert(h, 1);
+		}
+
+		for (key, refs) in self.overlay.keys().into_iter() {
+			let refs = *ret.get(&key).unwrap_or(&0) + refs;
+			ret.insert(key, refs);
+		}
+		ret
+	}
+
+	fn lookup(&self, key: &H256) -> Option<&[u8]> {
+		let k = self.overlay.raw(key);
+		match k {
+			Some(&(ref d, rc)) if rc > 0 => Some(d),
+			_ => {
+				if let Some(x) = self.payload(key) {
+					Some(&self.overlay.denote(key, x).0)
+				}
+				else {
+					None
+				}
+			}
+		}
+	}
+
+	fn exists(&self, key: &H256) -> bool {
+		self.lookup(key).is_some()
+	}
+
+	fn insert(&mut self, value: &[u8]) -> H256 {
+		self.overlay.insert(value)
+	}
+	fn emplace(&mut self, key: H256, value: Bytes) {
+		self.overlay.emplace(key, value);
+	}
+	fn kill(&mut self, key: &H256) {
+		self.overlay.kill(key);
+	}
+}
+
+impl JournalDB for OptionOneDB {
+	fn spawn(&self) -> Box<JournalDB> {
+		Box::new(OptionOneDB {
+			overlay: MemoryDB::new(),
+			backing: self.backing.clone(),
+			counters: self.counters.clone(),
+		})
+	}
+
+	fn mem_used(&self) -> usize {
+		self.overlay.mem_used() + match self.counters {
+			Some(ref c) => c.read().unwrap().heap_size_of_children(),
+			None => 0
+		}
+ 	}
+
+	fn is_empty(&self) -> bool {
+		self.backing.get(&LATEST_ERA_KEY).expect("Low level database error").is_none()
+	}
+
+	fn commit(&mut self, now: u64, id: &H256, end: Option<(u64, H256)>) -> Result<u32, UtilError> {
+		// journal format:
+		// [era, 0] => [ id, [insert_0, ...], [remove_0, ...] ]
+		// [era, 1] => [ id, [insert_0, ...], [remove_0, ...] ]
+		// [era, n] => [ ... ]
+
+		// TODO: store reclaim_period.
+
+		// When we make a new commit, we make a journal of all blocks in the recent history and record
+		// all keys that were inserted and deleted. The journal is ordered by era; multiple commits can
+		// share the same era. This forms a data structure similar to a queue but whose items are tuples.
+		// By the time comes to remove a tuple from the queue (i.e. then the era passes from recent history
+		// into ancient history) then only one commit from the tuple is considered canonical. This commit
+		// is kept in the main backing database, whereas any others from the same era are reverted.
+		//
+		// It is possible that a key, properly available in the backing database be deleted and re-inserted
+		// in the recent history queue, yet have both operations in commits that are eventually non-canonical.
+		// To avoid the original, and still required, key from being deleted, we maintain a reference count
+		// which includes an original key, if any.
+		//
+		// The semantics of the `counter` are:
+		// insert key k:
+		//   counter already contains k: count += 1
+		//   counter doesn't contain k:
+		//     backing db contains k: count = 1
+		//     backing db doesn't contain k: insert into backing db, count = 0
+		// delete key k:
+		//   counter contains k (count is asserted to be non-zero):
+		//     count > 1: counter -= 1
+		//     count == 1: remove counter
+		//     count == 0: remove key from backing db
+		//   counter doesn't contain k: remove key from backing db
+		//
+		// Practically, this means that for each commit block turning from recent to ancient we do the
+		// following:
+		// is_canonical:
+		//   inserts: Ignored (left alone in the backing database).
+		//   deletes: Enacted; however, recent history queue is checked for ongoing references. This is
+		//            reduced as a preference to deletion from the backing database.
+		// !is_canonical:
+		//   inserts: Reverted; however, recent history queue is checked for ongoing references. This is
+		//            reduced as a preference to deletion from the backing database.
+		//   deletes: Ignored (they were never inserted).
+		//
+
+		// record new commit's details.
+		trace!("commit: #{} ({}), end era: {:?}", now, id, end);
+		let mut counters = self.counters.as_ref().unwrap().write().unwrap();
+		let batch = DBTransaction::new();
+		{
+			let mut index = 0usize;
+			let mut last;
+
+			while try!(self.backing.get({
+				let mut r = RlpStream::new_list(3);
+				r.append(&now);
+				r.append(&index);
+				r.append(&&PADDING[..]);
+				last = r.drain();
+				&last
+			})).is_some() {
+				index += 1;
+			}
+
+			let drained = self.overlay.drain();
+			let removes: Vec<H256> = drained
+				.iter()
+				.filter_map(|(k, &(_, c))| if c < 0 {Some(k.clone())} else {None})
+				.collect();
+			let inserts: Vec<(H256, Bytes)> = drained
+				.into_iter()
+				.filter_map(|(k, (v, r))| if r > 0 { assert!(r == 1); Some((k, v)) } else { assert!(r >= -1); None })
+				.collect();
+
+			let mut r = RlpStream::new_list(3);
+			r.append(id);
+
+			// Process the new inserts.
+			// We use the inserts for three things. For each:
+			// - we place into the backing DB or increment the counter if already in;
+			// - we note in the backing db that it was already in;
+			// - we write the key into our journal for this block;
+
+			r.begin_list(inserts.len());
+			inserts.iter().foreach(|&(k, _)| {r.append(&k);});
+			r.append(&removes);
+			Self::insert_keys(&inserts, &self.backing, &mut counters, &batch);
+			try!(batch.put(&last, r.as_raw()));
+			try!(batch.put(&LATEST_ERA_KEY, &encode(&now)));
+		}
+
+		// apply old commits' details
+		if let Some((end_era, canon_id)) = end {
+			let mut index = 0usize;
+			let mut last;
+			while let Some(rlp_data) = try!(self.backing.get({
+				let mut r = RlpStream::new_list(3);
+				r.append(&end_era);
+				r.append(&index);
+				r.append(&&PADDING[..]);
+				last = r.drain();
+				&last
+			})) {
+				let rlp = Rlp::new(&rlp_data);
+				let inserts: Vec<H256> = rlp.val_at(1);
+				let deletes: Vec<H256> = rlp.val_at(2);
+				// Collect keys to be removed. These are removed keys for canonical block, inserted for non-canonical
+				Self::kill_keys(if canon_id == rlp.val_at(0) {deletes} else {inserts}, &mut counters, &batch);
+				try!(batch.delete(&last));
+				index += 1;
+			}
+			trace!("OptionOneDB: delete journal for time #{}.{}, (canon was {})", end_era, index, canon_id);
+		}
+
+		try!(self.backing.write(batch));
+//		trace!("OptionOneDB::commit() deleted {} nodes", deletes);
+		Ok(0)
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use common::*;
+	use super::*;
+	use hashdb::*;
+	use journaldb::traits::JournalDB;
+
+	#[test]
+	fn insert_same_in_fork() {
+		// history is 1
+		let mut jdb = OptionOneDB::new_temp();
+
+		let x = jdb.insert(b"X");
+		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		jdb.commit(3, &b"1002a".sha3(), Some((1, b"1".sha3()))).unwrap();
+		jdb.commit(4, &b"1003a".sha3(), Some((2, b"2".sha3()))).unwrap();
+
+		jdb.remove(&x);
+		jdb.commit(3, &b"1002b".sha3(), Some((1, b"1".sha3()))).unwrap();
+		let x = jdb.insert(b"X");
+		jdb.commit(4, &b"1003b".sha3(), Some((2, b"2".sha3()))).unwrap();
+
+		jdb.commit(5, &b"1004a".sha3(), Some((3, b"1002a".sha3()))).unwrap();
+		jdb.commit(6, &b"1005a".sha3(), Some((4, b"1003a".sha3()))).unwrap();
+
+		assert!(jdb.exists(&x));
+	}
+
+	#[test]
+	fn long_history() {
+		// history is 3
+		let mut jdb = OptionOneDB::new_temp();
+		let h = jdb.insert(b"foo");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.remove(&h);
+		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.commit(3, &b"3".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.exists(&h));
+		jdb.commit(4, &b"4".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(!jdb.exists(&h));
+	}
+
+	#[test]
+	fn complex() {
+		// history is 1
+		let mut jdb = OptionOneDB::new_temp();
+
+		let foo = jdb.insert(b"foo");
+		let bar = jdb.insert(b"bar");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+
+		jdb.remove(&foo);
+		jdb.remove(&bar);
+		let baz = jdb.insert(b"baz");
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+		assert!(jdb.exists(&baz));
+
+		let foo = jdb.insert(b"foo");
+		jdb.remove(&baz);
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(!jdb.exists(&bar));
+		assert!(jdb.exists(&baz));
+
+		jdb.remove(&foo);
+		jdb.commit(3, &b"3".sha3(), Some((2, b"2".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(!jdb.exists(&bar));
+		assert!(!jdb.exists(&baz));
+
+		jdb.commit(4, &b"4".sha3(), Some((3, b"3".sha3()))).unwrap();
+		assert!(!jdb.exists(&foo));
+		assert!(!jdb.exists(&bar));
+		assert!(!jdb.exists(&baz));
+	}
+
+	#[test]
+	fn fork() {
+		// history is 1
+		let mut jdb = OptionOneDB::new_temp();
+
+		let foo = jdb.insert(b"foo");
+		let bar = jdb.insert(b"bar");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+
+		jdb.remove(&foo);
+		let baz = jdb.insert(b"baz");
+		jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+		jdb.remove(&bar);
+		jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+		assert!(jdb.exists(&baz));
+
+		jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		assert!(!jdb.exists(&baz));
+		assert!(!jdb.exists(&bar));
+	}
+
+	#[test]
+	fn overwrite() {
+		// history is 1
+		let mut jdb = OptionOneDB::new_temp();
+
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.exists(&foo));
+
+		jdb.remove(&foo);
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		jdb.insert(b"foo");
+		assert!(jdb.exists(&foo));
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+		jdb.commit(3, &b"2".sha3(), Some((0, b"2".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+	}
+
+	#[test]
+	fn fork_same_key() {
+		// history is 1
+		let mut jdb = OptionOneDB::new_temp();
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+
+		let foo = jdb.insert(b"foo");
+		jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+		jdb.insert(b"foo");
+		jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+
+		jdb.commit(2, &b"2a".sha3(), Some((1, b"1a".sha3()))).unwrap();
+		assert!(jdb.exists(&foo));
+	}
+
+
+	#[test]
+	fn reopen() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+		let bar = H256::random();
+
+		let foo = {
+			let mut jdb = OptionOneDB::new(dir.to_str().unwrap());
+			// history is 1
+			let foo = jdb.insert(b"foo");
+			jdb.emplace(bar.clone(), b"bar".to_vec());
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			foo
+		};
+
+		{
+			let mut jdb = OptionOneDB::new(dir.to_str().unwrap());
+			jdb.remove(&foo);
+			jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		}
+
+		{
+			let mut jdb = OptionOneDB::new(dir.to_str().unwrap());
+			assert!(jdb.exists(&foo));
+			assert!(jdb.exists(&bar));
+			jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+			assert!(!jdb.exists(&foo));
+		}
+	}
+
+	#[test]
+	fn reopen_remove() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let foo = {
+			let mut jdb = OptionOneDB::new(dir.to_str().unwrap());
+			// history is 1
+			let foo = jdb.insert(b"foo");
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+			// foo is ancient history.
+
+			jdb.insert(b"foo");
+			jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+			foo
+		};
+
+		{
+			let mut jdb = OptionOneDB::new(dir.to_str().unwrap());
+			jdb.remove(&foo);
+			jdb.commit(3, &b"3".sha3(), Some((2, b"2".sha3()))).unwrap();
+			assert!(jdb.exists(&foo));
+			jdb.remove(&foo);
+			jdb.commit(4, &b"4".sha3(), Some((3, b"3".sha3()))).unwrap();
+			jdb.commit(5, &b"5".sha3(), Some((4, b"4".sha3()))).unwrap();
+			assert!(!jdb.exists(&foo));
+		}
+	}
+	#[test]
+	fn reopen_fork() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+		let (foo, bar, baz) = {
+			let mut jdb = OptionOneDB::new(dir.to_str().unwrap());
+			// history is 1
+			let foo = jdb.insert(b"foo");
+			let bar = jdb.insert(b"bar");
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			jdb.remove(&foo);
+			let baz = jdb.insert(b"baz");
+			jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+
+			jdb.remove(&bar);
+			jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+			(foo, bar, baz)
+		};
+
+		{
+			let mut jdb = OptionOneDB::new(dir.to_str().unwrap());
+			jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
+			assert!(jdb.exists(&foo));
+			assert!(!jdb.exists(&baz));
+			assert!(!jdb.exists(&bar));
+		}
+	}
+}

util/src/journaldb/overlay.rs

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Disk-backed HashDB implementation.
+//! JournalDB over in-memory overlay
 
 use common::*;
 use rlp::*;
@@ -23,13 +23,11 @@ use memorydb::*;
 use kvdb::{Database, DBTransaction, DatabaseConfig};
 #[cfg(test)]
 use std::env;
+use super::JournalDB;
 
-/// Implementation of the HashDB trait for a disk-backed database with a memory overlay
+/// Implementation of the JournalDB trait for a disk-backed database with a memory overlay
 /// and, possibly, latent-removal semantics.
 ///
-/// If `journal_overlay` is `None`, then it behaves exactly like OverlayDB. If not it behaves
-/// differently:
-///
 /// Like OverlayDB, there is a memory overlay; `commit()` must be called in order to
 /// write operations out to disk. Unlike OverlayDB, `remove()` operations do not take effect
 /// immediately. Rather some age (based on a linear but arbitrary metric) must pass before
@@ -58,10 +56,10 @@ use std::env;
 /// the removed key is not present in the history overlay.
 /// 7. Delete ancient record from memory and disk.
 /// 
-pub struct JournalDB {
+pub struct JournalOverlayDB {
 	transaction_overlay: MemoryDB,
 	backing: Arc<Database>,
-	journal_overlay: Option<Arc<RwLock<JournalOverlay>>>,
+	journal_overlay: Arc<RwLock<JournalOverlay>>,
 }
 
 #[derive(PartialEq)]
@@ -84,9 +82,9 @@ impl HeapSizeOf for JournalEntry {
 	}
 }
 
-impl Clone for JournalDB {
-	fn clone(&self) -> JournalDB {
-		JournalDB {
+impl Clone for JournalOverlayDB {
+	fn clone(&self) -> JournalOverlayDB {
+		JournalOverlayDB {
 			transaction_overlay: MemoryDB::new(),
 			backing: self.backing.clone(),
 			journal_overlay: self.journal_overlay.clone(),
@@ -97,45 +95,34 @@ impl Clone for JournalDB {
 // all keys must be at least 12 bytes
 const LATEST_ERA_KEY : [u8; 12] = [ b'l', b'a', b's', b't', 0, 0, 0, 0, 0, 0, 0, 0 ];
 const VERSION_KEY : [u8; 12] = [ b'j', b'v', b'e', b'r', 0, 0, 0, 0, 0, 0, 0, 0 ];
-
-const DB_VERSION : u32 = 3;
-const DB_VERSION_NO_JOURNAL : u32 = 3 + 256;
-
+const DB_VERSION : u32 = 0x200 + 3;
 const PADDING : [u8; 10] = [ 0u8; 10 ];
 
-impl JournalDB {
+impl JournalOverlayDB {
 	/// Create a new instance from file
-	pub fn new(path: &str) -> JournalDB {
-		Self::from_prefs(path, true)
+	pub fn new(path: &str) -> JournalOverlayDB {
+		Self::from_prefs(path)
 	}
 
 	/// Create a new instance from file
-	pub fn from_prefs(path: &str, prefer_journal: bool) -> JournalDB {
+	pub fn from_prefs(path: &str) -> JournalOverlayDB {
 		let opts = DatabaseConfig {
 			prefix_size: Some(12) //use 12 bytes as prefix, this must match account_db prefix
 		};
 		let backing = Database::open(&opts, path).unwrap_or_else(|e| {
 			panic!("Error opening state db: {}", e);
 		});
-		let with_journal;
 		if !backing.is_empty() {
 			match backing.get(&VERSION_KEY).map(|d| d.map(|v| decode::<u32>(&v))) {
-				Ok(Some(DB_VERSION)) => { with_journal = true; },
-				Ok(Some(DB_VERSION_NO_JOURNAL)) => { with_journal = false; },
+				Ok(Some(DB_VERSION)) => {}
 				v => panic!("Incompatible DB version, expected {}, got {:?}", DB_VERSION, v)
 			}
 		} else {
-			backing.put(&VERSION_KEY, &encode(&(if prefer_journal { DB_VERSION } else { DB_VERSION_NO_JOURNAL }))).expect("Error writing version to database");
-			with_journal = prefer_journal;
+			backing.put(&VERSION_KEY, &encode(&DB_VERSION)).expect("Error writing version to database");
 		}
 
-
-		let journal_overlay = if with_journal {
-			Some(Arc::new(RwLock::new(JournalDB::read_overlay(&backing))))
-		} else {
-			None
-		};
-		JournalDB {
+		let journal_overlay = Arc::new(RwLock::new(JournalOverlayDB::read_overlay(&backing)));
+		JournalOverlayDB {
 			transaction_overlay: MemoryDB::new(),
 			backing: Arc::new(backing),
 			journal_overlay: journal_overlay,
@@ -144,61 +131,92 @@ impl JournalDB {
 
 	/// Create a new instance with an anonymous temporary database.
 	#[cfg(test)]
-	pub fn new_temp() -> JournalDB {
+	pub fn new_temp() -> JournalOverlayDB {
 		let mut dir = env::temp_dir();
 		dir.push(H32::random().hex());
 		Self::new(dir.to_str().unwrap())
 	}
 
-	/// Check if this database has any commits
-	pub fn is_empty(&self) -> bool {
+	#[cfg(test)]
+	fn can_reconstruct_refs(&self) -> bool {
+		let reconstructed = Self::read_overlay(&self.backing);
+		let journal_overlay = self.journal_overlay.read().unwrap();
+		*journal_overlay == reconstructed
+	}
+
+	fn payload(&self, key: &H256) -> Option<Bytes> {
+		self.backing.get(&key.bytes()).expect("Low-level database error. Some issue with your hard disk?").map(|v| v.to_vec())
+	}
+
+	fn read_overlay(db: &Database) -> JournalOverlay {
+		let mut journal = HashMap::new();
+		let mut overlay = MemoryDB::new();
+		let mut count = 0;
+		let mut latest_era = 0;
+		if let Some(val) = db.get(&LATEST_ERA_KEY).expect("Low-level database error.") {
+			latest_era = decode::<u64>(&val);
+			let mut era = latest_era;
+			loop {
+				let mut index = 0usize;
+				while let Some(rlp_data) = db.get({
+					let mut r = RlpStream::new_list(3);
+					r.append(&era);
+					r.append(&index);
+					r.append(&&PADDING[..]);
+					&r.drain()
+				}).expect("Low-level database error.") {
+					trace!("read_overlay: era={}, index={}", era, index);
+					let rlp = Rlp::new(&rlp_data);
+					let id: H256 = rlp.val_at(0);
+					let insertions = rlp.at(1);
+					let deletions: Vec<H256> = rlp.val_at(2);
+					let mut inserted_keys = Vec::new();
+					for r in insertions.iter() {
+						let k: H256 = r.val_at(0);
+						let v: Bytes = r.val_at(1);
+						overlay.emplace(k.clone(), v);
+						inserted_keys.push(k);
+						count += 1;
+					}
+					journal.entry(era).or_insert_with(Vec::new).push(JournalEntry {
+						id: id,
+						insertions: inserted_keys,
+						deletions: deletions,
+					});
+					index += 1;
+				};
+				if index == 0 || era == 0 {
+					break;
+				}
+				era -= 1;
+			}
+		}
+		trace!("Recovered {} overlay entries, {} journal entries", count, journal.len());
+		JournalOverlay { backing_overlay: overlay, journal: journal, latest_era: latest_era }
+	}
+}
+
+impl JournalDB for JournalOverlayDB {
+	fn spawn(&self) -> Box<JournalDB> {
+		Box::new(self.clone())
+	}
+
+	fn mem_used(&self) -> usize {
+		let mut mem = self.transaction_overlay.mem_used();
+		let overlay = self.journal_overlay.read().unwrap();
+		mem += overlay.backing_overlay.mem_used();
+		mem += overlay.journal.heap_size_of_children();
+		mem
+	}
+
+	fn is_empty(&self) -> bool {
 		self.backing.get(&LATEST_ERA_KEY).expect("Low level database error").is_none()
 	}
 
-	/// Commit all recent insert operations.
-	pub fn commit(&mut self, now: u64, id: &H256, end: Option<(u64, H256)>) -> Result<(), UtilError> {
-		let have_journal_overlay = self.journal_overlay.is_some();
-		if have_journal_overlay {
-			self.commit_with_overlay(now, id, end)
-		} else {
-			self.commit_without_overlay()
-		}
-	}
-
-	/// Drain the overlay and place it into a batch for the DB.
-	fn batch_overlay_insertions(overlay: &mut MemoryDB, batch: &DBTransaction) -> usize {
-		let mut insertions = 0usize;
-		let mut deletions = 0usize;
-		for i in overlay.drain().into_iter() {
-			let (key, (value, rc)) = i;
-			if rc > 0 {
-				assert!(rc == 1);
-				batch.put(&key.bytes(), &value).expect("Low-level database error. Some issue with your hard disk?");
-				insertions += 1;
-			}
-			if rc < 0 {
-				assert!(rc == -1);
-				deletions += 1;
-			}
-		}
-		trace!("commit: Inserted {}, Deleted {} nodes", insertions, deletions);
-		insertions + deletions
-	}
-
-	/// Just commit the transaction overlay into the backing DB.
-	fn commit_without_overlay(&mut self) -> Result<(), UtilError> {
-		let batch = DBTransaction::new();
-		Self::batch_overlay_insertions(&mut self.transaction_overlay, &batch);
-		try!(self.backing.write(batch));
-		Ok(())
-	}
-
-	/// Commit all recent insert operations and historical removals from the old era
-	/// to the backing database.
-	fn commit_with_overlay(&mut self, now: u64, id: &H256, end: Option<(u64, H256)>) -> Result<(), UtilError> {
+	fn commit(&mut self, now: u64, id: &H256, end: Option<(u64, H256)>) -> Result<u32, UtilError> {
 		// record new commit's details.
 		trace!("commit: #{} ({}), end era: {:?}", now, id, end);
-		let mut journal_overlay = self.journal_overlay.as_mut().unwrap().write().unwrap();
+		let mut journal_overlay = self.journal_overlay.write().unwrap();
 		let batch = DBTransaction::new();
 		{
 			let mut r = RlpStream::new_list(3);
@@ -280,80 +298,12 @@ impl JournalDB {
 			journal_overlay.journal.remove(&end_era);
 		}
 		try!(self.backing.write(batch));
-		Ok(())
+		Ok(0)
 	}
 
-	#[cfg(test)]
-	fn can_reconstruct_refs(&self) -> bool {
-		let reconstructed = Self::read_overlay(&self.backing);
-		let journal_overlay = self.journal_overlay.as_ref().unwrap().read().unwrap();
-		*journal_overlay == reconstructed
-	}
-
-	fn payload(&self, key: &H256) -> Option<Bytes> {
-		self.backing.get(&key.bytes()).expect("Low-level database error. Some issue with your hard disk?").map(|v| v.to_vec())
-	}
-
-	fn read_overlay(db: &Database) -> JournalOverlay {
-		let mut journal = HashMap::new();
-		let mut overlay = MemoryDB::new();
-		let mut count = 0;
-		let mut latest_era = 0;
-		if let Some(val) = db.get(&LATEST_ERA_KEY).expect("Low-level database error.") {
-			latest_era = decode::<u64>(&val);
-			let mut era = latest_era;
-			loop {
-				let mut index = 0usize;
-				while let Some(rlp_data) = db.get({
-					let mut r = RlpStream::new_list(3);
-					r.append(&era);
-					r.append(&index);
-					r.append(&&PADDING[..]);
-					&r.drain()
-				}).expect("Low-level database error.") {
-					trace!("read_overlay: era={}, index={}", era, index);
-					let rlp = Rlp::new(&rlp_data);
-					let id: H256 = rlp.val_at(0);
-					let insertions = rlp.at(1);
-					let deletions: Vec<H256> = rlp.val_at(2);
-					let mut inserted_keys = Vec::new();
-					for r in insertions.iter() {
-						let k: H256 = r.val_at(0);
-						let v: Bytes = r.val_at(1);
-						overlay.emplace(k.clone(), v);
-						inserted_keys.push(k);
-						count += 1;
-					}
-					journal.entry(era).or_insert_with(Vec::new).push(JournalEntry {
-						id: id,
-						insertions: inserted_keys,
-						deletions: deletions,
-					});
-					index += 1;
-				};
-				if index == 0 || era == 0 {
-					break;
-				}
-				era -= 1;
-			}
-		}
-		trace!("Recovered {} overlay entries, {} journal entries", count, journal.len());
-		JournalOverlay { backing_overlay: overlay, journal: journal, latest_era: latest_era }
-	}
-
-	/// Returns heap memory size used
-	pub fn mem_used(&self) -> usize {
-		let mut mem = self.transaction_overlay.mem_used();
-		if let Some(ref overlay) = self.journal_overlay.as_ref() {
-			let overlay = overlay.read().unwrap();
-			mem += overlay.backing_overlay.mem_used();
-			mem += overlay.journal.heap_size_of_children();
-		}
-		mem
-	}
 }
 
-impl HashDB for JournalDB {
+impl HashDB for JournalOverlayDB {
 	fn keys(&self) -> HashMap<H256, i32> {
 		let mut ret: HashMap<H256, i32> = HashMap::new();
 		for (key, _) in self.backing.iter() {
@@ -373,7 +323,7 @@ impl HashDB for JournalDB {
 		match k {
 			Some(&(ref d, rc)) if rc > 0 => Some(d),
 			_ => {
-				let v = self.journal_overlay.as_ref().map_or(None, |ref j| j.read().unwrap().backing_overlay.lookup(key).map(|v| v.to_vec()));
+				let v = self.journal_overlay.read().unwrap().backing_overlay.lookup(key).map(|v| v.to_vec());
 				match v {
 					Some(x) => {
 						Some(&self.transaction_overlay.denote(key, x).0)
@@ -412,11 +362,12 @@ mod tests {
 	use super::*;
 	use hashdb::*;
 	use log::init_log;
+	use journaldb::JournalDB;
 
 	#[test]
 	fn insert_same_in_fork() {
 		// history is 1
-		let mut jdb = JournalDB::new_temp();
+		let mut jdb = JournalOverlayDB::new_temp();
 
 		let x = jdb.insert(b"X");
 		jdb.commit(1, &b"1".sha3(), None).unwrap();
@@ -446,7 +397,7 @@ mod tests {
 	#[test]
 	fn long_history() {
 		// history is 3
-		let mut jdb = JournalDB::new_temp();
+		let mut jdb = JournalOverlayDB::new_temp();
 		let h = jdb.insert(b"foo");
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
 		assert!(jdb.can_reconstruct_refs());
@@ -469,7 +420,7 @@ mod tests {
 	#[test]
 	fn complex() {
 		// history is 1
-		let mut jdb = JournalDB::new_temp();
+		let mut jdb = JournalOverlayDB::new_temp();
 
 		let foo = jdb.insert(b"foo");
 		let bar = jdb.insert(b"bar");
@@ -512,7 +463,7 @@ mod tests {
 	#[test]
 	fn fork() {
 		// history is 1
-		let mut jdb = JournalDB::new_temp();
+		let mut jdb = JournalOverlayDB::new_temp();
 
 		let foo = jdb.insert(b"foo");
 		let bar = jdb.insert(b"bar");
@@ -544,7 +495,7 @@ mod tests {
 	#[test]
 	fn overwrite() {
 		// history is 1
-		let mut jdb = JournalDB::new_temp();
+		let mut jdb = JournalOverlayDB::new_temp();
 
 		let foo = jdb.insert(b"foo");
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
@@ -569,7 +520,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 
-		let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
 		assert!(jdb.can_reconstruct_refs());
 
@@ -597,7 +548,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 
-		let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
 		assert!(jdb.can_reconstruct_refs());
 
@@ -625,7 +576,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 
-		let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
 		assert!(jdb.can_reconstruct_refs());
 
@@ -663,7 +614,7 @@ mod tests {
 		let bar = H256::random();
 
 		let foo = {
-			let mut jdb = JournalDB::new(dir.to_str().unwrap());
+			let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 			// history is 1
 			let foo = jdb.insert(b"foo");
 			jdb.emplace(bar.clone(), b"bar".to_vec());
@@ -673,14 +624,14 @@ mod tests {
 		};
 
 		{
-			let mut jdb = JournalDB::new(dir.to_str().unwrap());
+			let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 			jdb.remove(&foo);
 			jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
 			assert!(jdb.can_reconstruct_refs());
 		}
 
 		{
-			let mut jdb = JournalDB::new(dir.to_str().unwrap());
+			let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 			assert!(jdb.exists(&foo));
 			assert!(jdb.exists(&bar));
 			jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
@@ -695,7 +646,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 
-		let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 
 		// history is 4
 		let foo = jdb.insert(b"foo");
@@ -724,7 +675,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 
-		let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 
 		// history is 4
 		let foo = jdb.insert(b"foo");
@@ -773,7 +724,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 
-		let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 		// history is 1
 		let foo = jdb.insert(b"foo");
 		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
@@ -804,7 +755,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 
-		let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 		// history is 4
 		let foo = jdb.insert(b"foo");
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
@@ -844,7 +795,7 @@ mod tests {
 		let foo = b"foo".sha3();
 
 		{
-			let mut jdb = JournalDB::new(dir.to_str().unwrap());
+			let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 			// history is 1
 			jdb.insert(b"foo");
 			jdb.commit(0, &b"0".sha3(), None).unwrap();
@@ -865,7 +816,7 @@ mod tests {
 			assert!(jdb.exists(&foo));
 
 		// incantation to reopen the db
-		}; { let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		}; { let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 
 			jdb.remove(&foo);
 			jdb.commit(4, &b"4".sha3(), Some((2, b"2".sha3()))).unwrap();
@@ -873,14 +824,14 @@ mod tests {
 			assert!(jdb.exists(&foo));
 
 		// incantation to reopen the db
-		}; { let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		}; { let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 
 			jdb.commit(5, &b"5".sha3(), Some((3, b"3".sha3()))).unwrap();
 			assert!(jdb.can_reconstruct_refs());
 			assert!(jdb.exists(&foo));
 
 		// incantation to reopen the db
-		}; { let mut jdb = JournalDB::new(dir.to_str().unwrap());
+		}; { let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 
 			jdb.commit(6, &b"6".sha3(), Some((4, b"4".sha3()))).unwrap();
 			assert!(jdb.can_reconstruct_refs());
@@ -893,7 +844,7 @@ mod tests {
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());
 		let (foo, bar, baz) = {
-			let mut jdb = JournalDB::new(dir.to_str().unwrap());
+			let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 			// history is 1
 			let foo = jdb.insert(b"foo");
 			let bar = jdb.insert(b"bar");
@@ -911,7 +862,7 @@ mod tests {
 		};
 
 		{
-			let mut jdb = JournalDB::new(dir.to_str().unwrap());
+			let mut jdb = JournalOverlayDB::new(dir.to_str().unwrap());
 			jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
 			assert!(jdb.can_reconstruct_refs());
 			assert!(jdb.exists(&foo));

util/src/journaldb/traits.rs

@@ -0,0 +1,37 @@
+// 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/>.
+
+//! Disk-backed HashDB implementation.
+
+use common::*;
+use hashdb::*;
+
+/// A HashDB which can manage a short-term journal potentially containing many forks of mutually
+/// exclusive actions.
+pub trait JournalDB : HashDB + Send + Sync {
+	/// Return a copy of ourself, in a box.
+	fn spawn(&self) -> Box<JournalDB>;
+
+	/// Returns heap memory size used
+	fn mem_used(&self) -> usize;
+
+	/// Check if this database has any commits
+	fn is_empty(&self) -> bool;
+
+	/// Commit all recent insert operations and canonical historical commits' removals from the
+	/// old era to the backing database, reverting any non-canonical historical commit's inserts.
+	fn commit(&mut self, now: u64, id: &H256, end: Option<(u64, H256)>) -> Result<u32, UtilError>;
+}

util/src/keys/store.rs

@@ -78,6 +78,59 @@ struct AccountUnlock {
 	expires: DateTime<UTC>,
 }
 
+/// Basic account management trait
+pub trait AccountProvider : Send + Sync {
+	/// Lists all accounts
+	fn accounts(&self) -> Result<Vec<Address>, ::std::io::Error>;
+	/// Unlocks account with the password provided
+	fn unlock_account(&self, account: &Address, pass: &str) -> Result<(), EncryptedHashMapError>;
+	/// Creates account
+	fn new_account(&self, pass: &str) -> Result<Address, ::std::io::Error>;
+	/// Returns secret for unlocked account
+	fn account_secret(&self, account: &Address) -> Result<crypto::Secret, SigningError>;
+	/// Returns secret for unlocked account
+	fn sign(&self, account: &Address, message: &H256) -> Result<crypto::Signature, SigningError>;
+}
+
+/// Thread-safe accounts management
+pub struct AccountService {
+	secret_store: RwLock<SecretStore>,
+}
+
+impl AccountProvider for AccountService {
+	/// Lists all accounts
+	fn accounts(&self) -> Result<Vec<Address>, ::std::io::Error> {
+		Ok(try!(self.secret_store.read().unwrap().accounts()).iter().map(|&(addr, _)| addr).collect::<Vec<Address>>())
+	}
+	/// Unlocks account with the password provided
+	fn unlock_account(&self, account: &Address, pass: &str) -> Result<(), EncryptedHashMapError> {
+		self.secret_store.read().unwrap().unlock_account(account, pass)
+	}
+	/// Creates account
+	fn new_account(&self, pass: &str) -> Result<Address, ::std::io::Error> {
+		self.secret_store.write().unwrap().new_account(pass)
+	}
+	/// Returns secret for unlocked account
+	fn account_secret(&self, account: &Address) -> Result<crypto::Secret, SigningError> {
+		self.secret_store.read().unwrap().account_secret(account)
+	}
+	/// Returns secret for unlocked account
+	fn sign(&self, account: &Address, message: &H256) -> Result<crypto::Signature, SigningError> {
+		self.secret_store.read().unwrap().sign(account, message)
+	}
+}
+
+impl AccountService {
+	/// New account service with the default location
+	pub fn new() -> AccountService {
+		let secret_store = RwLock::new(SecretStore::new());
+		secret_store.write().unwrap().try_import_existing();
+		AccountService {
+			secret_store: secret_store
+		}
+	}
+}
+
 impl SecretStore {
 	/// new instance of Secret Store in default home directory
 	pub fn new() -> SecretStore {

util/src/lib.rs

@@ -15,18 +15,18 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 #![warn(missing_docs)]
-#![cfg_attr(all(nightly, feature="dev"), feature(plugin))]
-#![cfg_attr(all(nightly, feature="dev"), plugin(clippy))]
+#![cfg_attr(feature="dev", feature(plugin))]
+#![cfg_attr(feature="dev", plugin(clippy))]
 
 // Clippy settings
 // TODO [todr] not really sure
-#![cfg_attr(all(nightly, feature="dev"), allow(needless_range_loop))]
+#![cfg_attr(feature="dev", allow(needless_range_loop))]
 // Shorter than if-else
-#![cfg_attr(all(nightly, feature="dev"), allow(match_bool))]
+#![cfg_attr(feature="dev", allow(match_bool))]
 // We use that to be more explicit about handled cases
-#![cfg_attr(all(nightly, feature="dev"), allow(match_same_arms))]
+#![cfg_attr(feature="dev", allow(match_same_arms))]
 // Keeps consistency (all lines with `.clone()`) and helpful when changing ref to non-ref.
-#![cfg_attr(all(nightly, feature="dev"), allow(clone_on_copy))]
+#![cfg_attr(feature="dev", allow(clone_on_copy))]
 
 //! Ethcore-util library
 //!
@@ -154,7 +154,7 @@ pub use rlp::*;
 pub use hashdb::*;
 pub use memorydb::*;
 pub use overlaydb::*;
-pub use journaldb::*;
+pub use journaldb::JournalDB;
 pub use math::*;
 pub use crypto::*;
 pub use triehash::*;

util/src/network/discovery.rs

@@ -243,7 +243,7 @@ impl Discovery {
 		self.send_to(packet, address.clone());
 	}
 
-	#[cfg_attr(all(nightly, feature="dev"), allow(map_clone))]
+	#[cfg_attr(feature="dev", allow(map_clone))]
 	fn nearest_node_entries(target: &NodeId, buckets: &[NodeBucket]) -> Vec<NodeEntry> {
 		let mut found: BTreeMap<u32, Vec<&NodeEntry>> = BTreeMap::new();
 		let mut count = 0;

util/src/network/host.rs

@@ -507,7 +507,7 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 		debug!(target: "network", "Connecting peers: {} sessions, {} pending", self.session_count(), self.handshake_count());
 	}
 
-	#[cfg_attr(all(nightly, feature="dev"), allow(single_match))]
+	#[cfg_attr(feature="dev", allow(single_match))]
 	fn connect_peer(&self, id: &NodeId, io: &IoContext<NetworkIoMessage<Message>>) {
 		if self.have_session(id)
 		{
@@ -542,7 +542,7 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 		self.create_connection(socket, Some(id), io);
 	}
 
-	#[cfg_attr(all(nightly, feature="dev"), allow(block_in_if_condition_stmt))]
+	#[cfg_attr(feature="dev", allow(block_in_if_condition_stmt))]
 	fn create_connection(&self, socket: TcpStream, id: Option<&NodeId>, io: &IoContext<NetworkIoMessage<Message>>) {
 		let nonce = self.info.write().unwrap().next_nonce();
 		let mut handshakes = self.handshakes.write().unwrap();

util/src/overlaydb.rs

@@ -36,6 +36,7 @@ use kvdb::{Database};
 ///
 /// `lookup()` and `contains()` maintain normal behaviour - all `insert()` and `remove()` 
 /// queries have an immediate effect in terms of these functions.
+//#[derive(Clone)]
 pub struct OverlayDB {
 	overlay: MemoryDB,
 	backing: Arc<Database>,

util/src/panics.rs

@@ -71,7 +71,7 @@ impl PanicHandler {
 
 	/// Invoke closure and catch any possible panics.
 	/// In case of panic notifies all listeners about it.
-	#[cfg_attr(all(nightly, feature="dev"), allow(deprecated))]
+	#[cfg_attr(feature="dev", allow(deprecated))]
 	pub fn catch_panic<G, R>(&self, g: G) -> thread::Result<R> where G: FnOnce() -> R + Send + 'static {
 		let _guard = PanicGuard { handler: self };
 		let result = g();

util/src/trie/triedb.rs

@@ -54,7 +54,7 @@ pub struct TrieDB<'db> {
 	pub hash_count: usize,
 }
 
-#[cfg_attr(all(nightly, feature="dev"), allow(wrong_self_convention))]
+#[cfg_attr(feature="dev", allow(wrong_self_convention))]
 impl<'db> TrieDB<'db> {
 	/// Create a new trie with the backing database `db` and `root`
 	/// Panics, if `root` does not exist

util/src/trie/triedbmut.rs

@@ -66,7 +66,7 @@ enum MaybeChanged<'a> {
 	Changed(Bytes),
 }
 
-#[cfg_attr(all(nightly, feature="dev"), allow(wrong_self_convention))]
+#[cfg_attr(feature="dev", allow(wrong_self_convention))]
 impl<'db> TrieDBMut<'db> {
 	/// Create a new trie with the backing database `db` and empty `root`
 	/// Initialise to the state entailed by the genesis block.
@@ -350,7 +350,7 @@ impl<'db> TrieDBMut<'db> {
 		}
 	}
 
-	#[cfg_attr(all(nightly, feature="dev"), allow(cyclomatic_complexity))]
+	#[cfg_attr(feature="dev", allow(cyclomatic_complexity))]
 	/// Determine the RLP of the node, assuming we're inserting `partial` into the
 	/// node currently of data `old`. This will *not* delete any hash of `old` from the database;
 	/// it will just return the new RLP that includes the new node.