Merge branch 'tx_queue_integration' into tx_queue_rpc

2016-03-04 12:34:34 +01:00 · 2016-03-04 12:34:34 +01:00 · 410bd263dd
commit 410bd263dd
parent c889d9b3eb f7371daca3
66 changed files with 1379 additions and 710 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -44,6 +44,18 @@ dependencies = [
 "syntex_syntax 0.29.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

+[[package]]
+name = "bigint"
+version = "0.1.0"
+dependencies = [
+ "arrayvec 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "heapsize 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.18 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "bitflags"
 version = "0.3.3"
@ -211,11 +223,13 @@ name = "ethcore-rpc"
 version = "0.9.99"
 dependencies = [
 "clippy 0.0.44 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ethash 0.9.99",
 "ethcore 0.9.99",
 "ethcore-util 0.9.99",
 "ethsync 0.9.99",
 "jsonrpc-core 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "jsonrpc-http-server 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-serialize 0.3.18 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_codegen 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
@ -228,6 +242,7 @@ name = "ethcore-util"
 version = "0.9.99"
 dependencies = [
 "arrayvec 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bigint 0.1.0",
 "clippy 0.0.44 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "elastic-array 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
--- a/ethash/src/compute.rs
+++ b/ethash/src/compute.rs
@ -172,7 +172,8 @@ fn get_data_size(block_number: u64) -> usize {
 }

 #[inline]
-fn get_seedhash(block_number: u64) -> H256 {
+/// Given the `block_number`, determine the seed hash for Ethash.
+pub fn get_seedhash(block_number: u64) -> H256 {
 	let epochs = block_number / ETHASH_EPOCH_LENGTH;
 	let mut ret: H256 = [0u8; 32];
 	for _ in 0..epochs {
--- a/ethash/src/lib.rs
+++ b/ethash/src/lib.rs
@ -24,7 +24,7 @@ mod compute;

 use std::mem;
 use compute::Light;
-pub use compute::{quick_get_difficulty, H256, ProofOfWork, ETHASH_EPOCH_LENGTH};
+pub use compute::{get_seedhash, quick_get_difficulty, H256, ProofOfWork, ETHASH_EPOCH_LENGTH};

 use std::sync::{Arc, Mutex};

@ -35,7 +35,7 @@ struct LightCache {
 	prev: Option<Arc<Light>>,
 }

-/// Lighy/Full cache manager
+/// Light/Full cache manager.
 pub struct EthashManager {
 	cache: Mutex<LightCache>,
 }
--- a/ethcore/res/ethereum/tests
+++ b/ethcore/res/ethereum/tests
@ -1 +1 @@
-Subproject commit f32954b3ddb5af2dc3dc9ec6d9a28bee848fdf70
+Subproject commit 99afe8f5aad7bca5d0f1b1685390a4dea32d73c3
--- a/ethcore/src/action_params.rs
+++ b/ethcore/src/action_params.rs
@ -15,9 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

 //! Evm input params.
-use util::hash::*;
-use util::uint::*;
-use util::bytes::*;
+use common::*;

 /// Transaction value
 #[derive(Clone, Debug)]
--- a/ethcore/src/block.rs
+++ b/ethcore/src/block.rs
@ -21,7 +21,7 @@
 use common::*;
 use engine::*;
 use state::*;
-use verification::PreVerifiedBlock;
+use verification::PreverifiedBlock;

 /// A block, encoded as it is on the block chain.
 // TODO: rename to Block
@ -155,9 +155,9 @@ pub struct OpenBlock<'x> {
 /// Just like OpenBlock, except that we've applied `Engine::on_close_block`, finished up the non-seal header fields,
 /// and collected the uncles.
 ///
-/// There is no function available to push a transaction. If you want that you'll need to `reopen()` it.
-pub struct ClosedBlock<'x> {
-	open_block: OpenBlock<'x>,
+/// There is no function available to push a transaction.
+pub struct ClosedBlock {
+	block: ExecutedBlock,
 	uncle_bytes: Bytes,
 }

@ -178,10 +178,12 @@ impl<'x> OpenBlock<'x> {
 			last_hashes: last_hashes,
 		};

-		r.block.base.header.set_number(parent.number() + 1);
-		r.block.base.header.set_author(author);
-		r.block.base.header.set_extra_data(extra_data);
-		r.block.base.header.set_timestamp_now();
+		r.block.base.header.parent_hash = parent.hash();
+		r.block.base.header.number = parent.number + 1;
+		r.block.base.header.author = author;
+		r.block.base.header.set_timestamp_now(parent.timestamp());
+		r.block.base.header.extra_data = extra_data;
+		r.block.base.header.note_dirty();

 		engine.populate_from_parent(&mut r.block.base.header, parent);
 		engine.on_new_block(&mut r.block);
@ -259,7 +261,7 @@ impl<'x> OpenBlock<'x> {
 	}

 	/// Turn this into a `ClosedBlock`. A BlockChain must be provided in order to figure out the uncles.
-	pub fn close(self) -> ClosedBlock<'x> {
+	pub fn close(self) -> ClosedBlock {
 		let mut s = self;
 		s.engine.on_close_block(&mut s.block);
 		s.block.base.header.transactions_root = ordered_trie_root(s.block.base.transactions.iter().map(|ref e| e.rlp_bytes().to_vec()).collect());
@ -271,7 +273,10 @@ impl<'x> OpenBlock<'x> {
 		s.block.base.header.gas_used = s.block.receipts.last().map_or(U256::zero(), |r| r.gas_used);
 		s.block.base.header.note_dirty();

-		ClosedBlock::new(s, uncle_bytes)
+		ClosedBlock {
+			block: s.block, 
+			uncle_bytes: uncle_bytes,
+		}
 	}
 }

@ -279,38 +284,40 @@ impl<'x> IsBlock for OpenBlock<'x> {
 	fn block(&self) -> &ExecutedBlock { &self.block }
 }

-impl<'x> IsBlock for ClosedBlock<'x> {
-	fn block(&self) -> &ExecutedBlock { &self.open_block.block }
+impl<'x> IsBlock for ClosedBlock {
+	fn block(&self) -> &ExecutedBlock { &self.block }
 }

-impl<'x> ClosedBlock<'x> {
-	fn new(open_block: OpenBlock<'x>, uncle_bytes: Bytes) -> Self {
-		ClosedBlock {
-			open_block: open_block,
-			uncle_bytes: uncle_bytes,
-		}
-	}
-
+impl ClosedBlock {
 	/// Get the hash of the header without seal arguments.
 	pub fn hash(&self) -> H256 { self.header().rlp_sha3(Seal::Without) }

 	/// Provide a valid seal in order to turn this into a `SealedBlock`.
 	///
 	/// NOTE: This does not check the validity of `seal` with the engine.
-	pub fn seal(self, seal: Vec<Bytes>) -> Result<SealedBlock, BlockError> {
+	pub fn seal(self, engine: &Engine, seal: Vec<Bytes>) -> Result<SealedBlock, BlockError> {
 		let mut s = self;
-		if seal.len() != s.open_block.engine.seal_fields() {
-			return Err(BlockError::InvalidSealArity(Mismatch{expected: s.open_block.engine.seal_fields(), found: seal.len()}));
+		if seal.len() != engine.seal_fields() {
+			return Err(BlockError::InvalidSealArity(Mismatch{expected: engine.seal_fields(), found: seal.len()}));
 		}
-		s.open_block.block.base.header.set_seal(seal);
-		Ok(SealedBlock { block: s.open_block.block, uncle_bytes: s.uncle_bytes })
+		s.block.base.header.set_seal(seal);
+		Ok(SealedBlock { block: s.block, uncle_bytes: s.uncle_bytes })
 	}

-	/// Turn this back into an `OpenBlock`.
-	pub fn reopen(self) -> OpenBlock<'x> { self.open_block }
+	/// Provide a valid seal in order to turn this into a `SealedBlock`.
+	/// This does check the validity of `seal` with the engine.
+	/// Returns the `ClosedBlock` back again if the seal is no good.
+	pub fn try_seal(self, engine: &Engine, seal: Vec<Bytes>) -> Result<SealedBlock, ClosedBlock> {
+		let mut s = self;
+		s.block.base.header.set_seal(seal);
+		match engine.verify_block_seal(&s.block.base.header) {
+			Err(_) => Err(s),
+			_ => Ok(SealedBlock { block: s.block, uncle_bytes: s.uncle_bytes }),
+		}
+	}

 	/// Drop this object and return the underlieing database.
-	pub fn drain(self) -> JournalDB { self.open_block.block.state.drop().1 }
+	pub fn drain(self) -> JournalDB { self.block.state.drop().1 }
 }

 impl SealedBlock {
@ -332,7 +339,7 @@ impl IsBlock for SealedBlock {
 }

 /// Enact the block given by block header, transactions and uncles
-pub fn enact<'x>(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock<'x>, Error> {
+pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	{
 		if ::log::max_log_level() >= ::log::LogLevel::Trace {
 			let s = State::from_existing(db.clone(), parent.state_root().clone(), engine.account_start_nonce());
@ -350,14 +357,14 @@ pub fn enact<'x>(header: &Header, transactions: &[SignedTransaction], uncles: &[
 }

 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_bytes<'x>(block_bytes: &[u8], engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock<'x>, Error> {
+pub fn enact_bytes(block_bytes: &[u8], engine: &Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	let block = BlockView::new(block_bytes);
 	let header = block.header();
 	enact(&header, &block.transactions(), &block.uncles(), engine, db, parent, last_hashes)
 }

 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_verified<'x>(block: &PreVerifiedBlock, engine: &'x Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock<'x>, Error> {
+pub fn enact_verified(block: &PreverifiedBlock, engine: &Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	let view = BlockView::new(&block.bytes);
 	enact(&block.header, &block.transactions, &view.uncles(), engine, db, parent, last_hashes)
 }
@ -365,7 +372,7 @@ pub fn enact_verified<'x>(block: &PreVerifiedBlock, engine: &'x Engine, db: Jour
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header. Seal the block aferwards
 pub fn enact_and_seal(block_bytes: &[u8], engine: &Engine, db: JournalDB, parent: &Header, last_hashes: LastHashes) -> Result<SealedBlock, Error> {
 	let header = BlockView::new(block_bytes).header_view();
-	Ok(try!(try!(enact_bytes(block_bytes, engine, db, parent, last_hashes)).seal(header.seal())))
+	Ok(try!(try!(enact_bytes(block_bytes, engine, db, parent, last_hashes)).seal(engine, header.seal())))
 }

 #[cfg(test)]
@ -386,7 +393,7 @@ mod tests {
 		let last_hashes = vec![genesis_header.hash()];
 		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), vec![]);
 		let b = b.close();
-		let _ = b.seal(vec![]);
+		let _ = b.seal(engine.deref(), vec![]);
 	}

 	#[test]
@ -398,7 +405,7 @@ mod tests {
 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(&mut db);
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), vec![]).close().seal(vec![]).unwrap();
+		let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), vec![]).close().seal(engine.deref(), vec![]).unwrap();
 		let orig_bytes = b.rlp_bytes();
 		let orig_db = b.drain();

--- a/ethcore/src/block_queue.rs
+++ b/ethcore/src/block_queue.rs
@ -28,7 +28,7 @@ use service::*;
 use client::BlockStatus;
 use util::panics::*;

-known_heap_size!(0, UnVerifiedBlock, VerifyingBlock, PreVerifiedBlock);
+known_heap_size!(0, UnverifiedBlock, VerifyingBlock, PreverifiedBlock);

 const MIN_MEM_LIMIT: usize = 16384;
 const MIN_QUEUE_LIMIT: usize = 512;
@ -105,14 +105,14 @@ pub struct BlockQueue {
 	max_mem_use: usize,
 }

-struct UnVerifiedBlock {
+struct UnverifiedBlock {
 	header: Header,
 	bytes: Bytes,
 }

 struct VerifyingBlock {
 	hash: H256,
-	block: Option<PreVerifiedBlock>,
+	block: Option<PreverifiedBlock>,
 }

 struct QueueSignal {
@ -134,8 +134,8 @@ impl QueueSignal {

 #[derive(Default)]
 struct Verification {
-	unverified: VecDeque<UnVerifiedBlock>,
-	verified: VecDeque<PreVerifiedBlock>,
+	unverified: VecDeque<UnverifiedBlock>,
+	verified: VecDeque<PreverifiedBlock>,
 	verifying: VecDeque<VerifyingBlock>,
 	bad: HashSet<H256>,
 }
@ -244,7 +244,7 @@ impl BlockQueue {
 		}
 	}

-	fn drain_verifying(verifying: &mut VecDeque<VerifyingBlock>, verified: &mut VecDeque<PreVerifiedBlock>, bad: &mut HashSet<H256>) {
+	fn drain_verifying(verifying: &mut VecDeque<VerifyingBlock>, verified: &mut VecDeque<PreverifiedBlock>, bad: &mut HashSet<H256>) {
 		while !verifying.is_empty() && verifying.front().unwrap().block.is_some() {
 			let block = verifying.pop_front().unwrap().block.unwrap();
 			if bad.contains(&block.header.parent_hash) {
@ -289,31 +289,31 @@ impl BlockQueue {
 		let header = BlockView::new(&bytes).header();
 		let h = header.hash();
 		if self.processing.read().unwrap().contains(&h) {
-			return Err(ImportError::AlreadyQueued);
+			return Err(x!(ImportError::AlreadyQueued));
 		}
 		{
 			let mut verification = self.verification.lock().unwrap();
 			if verification.bad.contains(&h) {
-				return Err(ImportError::Bad(None));
+				return Err(x!(ImportError::KnownBad));
 			}

 			if verification.bad.contains(&header.parent_hash) {
 				verification.bad.insert(h.clone());
-				return Err(ImportError::Bad(None));
+				return Err(x!(ImportError::KnownBad));
 			}
 		}

 		match verify_block_basic(&header, &bytes, self.engine.deref().deref()) {
 			Ok(()) => {
 				self.processing.write().unwrap().insert(h.clone());
-				self.verification.lock().unwrap().unverified.push_back(UnVerifiedBlock { header: header, bytes: bytes });
+				self.verification.lock().unwrap().unverified.push_back(UnverifiedBlock { header: header, bytes: bytes });
 				self.more_to_verify.notify_all();
 				Ok(h)
 			},
 			Err(err) => {
 				warn!(target: "client", "Stage 1 block verification failed for {}\nError: {:?}", BlockView::new(&bytes).header_view().sha3(), err);
 				self.verification.lock().unwrap().bad.insert(h.clone());
-				Err(From::from(err))
+				Err(err)
 			}
 		}
 	}
@ -352,7 +352,7 @@ impl BlockQueue {
 	}

 	/// Removes up to `max` verified blocks from the queue
-	pub fn drain(&mut self, max: usize) -> Vec<PreVerifiedBlock> {
+	pub fn drain(&mut self, max: usize) -> Vec<PreverifiedBlock> {
 		let mut verification = self.verification.lock().unwrap();
 		let count = min(max, verification.verified.len());
 		let mut result = Vec::with_capacity(count);
@ -455,7 +455,7 @@ mod tests {
 		match duplicate_import {
 			Err(e) => {
 				match e {
-					ImportError::AlreadyQueued => {},
+					Error::Import(ImportError::AlreadyQueued) => {},
 					_ => { panic!("must return AlreadyQueued error"); }
 				}
 			}
--- a/ethcore/src/blockchain/best_block.rs
+++ b/ethcore/src/blockchain/best_block.rs
@ -14,8 +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/>.

-use util::hash::H256;
-use util::uint::U256;
+use util::numbers::{U256,H256};
 use header::BlockNumber;

 /// Best block info.
--- a/ethcore/src/blockchain/block_info.rs
+++ b/ethcore/src/blockchain/block_info.rs
@ -14,8 +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/>.

-use util::hash::H256;
-use util::uint::U256;
+use util::numbers::{U256,H256};
 use header::BlockNumber;

 /// Brief info about inserted block.
--- a/ethcore/src/blockchain/blockchain.rs
+++ b/ethcore/src/blockchain/blockchain.rs
@ -473,6 +473,12 @@ impl BlockChain {
 		self.extras_db.write(batch).unwrap();
 	}

+	/// Given a block's `parent`, find every block header which represents a valid uncle.
+	pub fn find_uncle_headers(&self, _parent: &H256) -> Vec<Header> {
+		// TODO
+		Vec::new()
+	}
+
 	/// Get inserted block info which is critical to preapre extras updates.
 	fn block_info(&self, block_bytes: &[u8]) -> BlockInfo {
 		let block = BlockView::new(block_bytes);
@ -770,14 +776,15 @@ mod tests {
 	use blockchain::{BlockProvider, BlockChain, BlockChainConfig};
 	use tests::helpers::*;
 	use devtools::*;
-	use blockchain::helpers::generators::ChainGenerator;
+	use blockchain::generator::{ChainGenerator, ChainIterator, BlockFinalizer};
 	use views::BlockView;

 	#[test]
 	fn basic_blockchain_insert() {
 		let mut canon_chain = ChainGenerator::default();
-		let genesis = canon_chain.next().unwrap();
-		let first = canon_chain.next().unwrap();
+		let mut finalizer = BlockFinalizer::default();
+		let genesis = canon_chain.generate(&mut finalizer).unwrap();
+		let first = canon_chain.generate(&mut finalizer).unwrap();
 		let genesis_hash = BlockView::new(&genesis).header_view().sha3();
 		let first_hash = BlockView::new(&first).header_view().sha3();

@ -805,20 +812,22 @@ mod tests {
 	#[test]
 	#[cfg_attr(feature="dev", allow(cyclomatic_complexity))]
 	fn test_small_fork() {
-		let genesis = "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".from_hex().unwrap();
-		let b1 = "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".from_hex().unwrap();
-		let b2 = "f902ccf901f9a0437e51676ff10756fcfee5edd9159fa41dbcb1b2c592850450371cbecd54ee4fa01dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347948888f1f195afa192cfee860698584c030f4c9db1a0c70a5dc56146e5ef025e4e5726a6373c6f12fd2f6784093a19ead0a7d17fb292a040645cbce4fd399e7bb9160b4c30c40d7ee616a030d4e18ef0ed3b02bdb65911a086e608555f63628417032a011d107b36427af37d153f0da02ce3f90fdd5e8c08b90100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008302004002832fefd882c0e384562791e880a0e3cc39ff775cc0a32f175995b92e84b729e5c9a3563ff899e3555b908bc21d75887c3cde283f4846a6f8cdf8cb01018304cb2f8080b87e6060604052606e8060106000396000f360606040526000357c010000000000000000000000000000000000000000000000000000000090048063c0406226146037576035565b005b60406004506056565b6040518082815260200191505060405180910390f35b6000600560006000508190555060059050606b565b90561ba05258615c63503c0a600d6994b12ea5750d45b3c69668e2a371b4fbfb9eeff6b8a0a11be762bc90491231274a2945be35a43f23c27775b1ff24dd521702fe15f73ec0".from_hex().unwrap();
-		let b3a = "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".from_hex().unwrap();
-		let b3b = "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".from_hex().unwrap();
+		let mut canon_chain = ChainGenerator::default();
+		let mut finalizer = BlockFinalizer::default();
+		let genesis = canon_chain.generate(&mut finalizer).unwrap();
+		let b1 = canon_chain.generate(&mut finalizer).unwrap();
+		let b2 = canon_chain.generate(&mut finalizer).unwrap();
+		let b3b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
+		let b3a = canon_chain.generate(&mut finalizer).unwrap();

-		let genesis_hash = H256::from_str("5716670833ec874362d65fea27a7cd35af5897d275b31a44944113111e4e96d2").unwrap();
-		let b1_hash = H256::from_str("437e51676ff10756fcfee5edd9159fa41dbcb1b2c592850450371cbecd54ee4f").unwrap();
-		let b2_hash = H256::from_str("36fde1253128666fcb95a5956da14a73489e988bb72738717ec1d31e1cee781a").unwrap();
-		let b3a_hash = H256::from_str("c208f88c9f5bf7e00840439742c12e5226d9752981f3ec0521bdcb6dd08af277").unwrap();
-		let b3b_hash = H256::from_str("bf72270ae0d95c9ea39a6adab994793fddb8c10fba7391e26279474124605d54").unwrap();
+		let genesis_hash = BlockView::new(&genesis).header_view().sha3();
+		let b1_hash= BlockView::new(&b1).header_view().sha3();
+		let b2_hash= BlockView::new(&b2).header_view().sha3();
+		let b3a_hash= BlockView::new(&b3a).header_view().sha3();
+		let b3b_hash= BlockView::new(&b3b).header_view().sha3();

 		// b3a is a part of canon chain, whereas b3b is part of sidechain
-		let best_block_hash = H256::from_str("c208f88c9f5bf7e00840439742c12e5226d9752981f3ec0521bdcb6dd08af277").unwrap();
+		let best_block_hash = b3a_hash.clone();

 		let temp = RandomTempPath::new();
 		let bc = BlockChain::new(BlockChainConfig::default(), &genesis, temp.as_path());
@ -893,22 +902,24 @@ mod tests {

 	#[test]
 	fn test_reopen_blockchain_db() {
-		let genesis = "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".from_hex().unwrap();
-		let b1 = "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".from_hex().unwrap();
-		let genesis_hash = H256::from_str("5716670833ec874362d65fea27a7cd35af5897d275b31a44944113111e4e96d2").unwrap();
-		let b1_hash = H256::from_str("437e51676ff10756fcfee5edd9159fa41dbcb1b2c592850450371cbecd54ee4f").unwrap();
+		let mut canon_chain = ChainGenerator::default();
+		let mut finalizer = BlockFinalizer::default();
+		let genesis = canon_chain.generate(&mut finalizer).unwrap();
+		let first = canon_chain.generate(&mut finalizer).unwrap();
+		let genesis_hash = BlockView::new(&genesis).header_view().sha3();
+		let first_hash = BlockView::new(&first).header_view().sha3();

 		let temp = RandomTempPath::new();
 		{
 			let bc = BlockChain::new(BlockChainConfig::default(), &genesis, temp.as_path());
 			assert_eq!(bc.best_block_hash(), genesis_hash);
-			bc.insert_block(&b1, vec![]);
-			assert_eq!(bc.best_block_hash(), b1_hash);
+			bc.insert_block(&first, vec![]);
+			assert_eq!(bc.best_block_hash(), first_hash);
 		}

 		{
 			let bc = BlockChain::new(BlockChainConfig::default(), &genesis, temp.as_path());
-			assert_eq!(bc.best_block_hash(), b1_hash);
+			assert_eq!(bc.best_block_hash(), first_hash);
 		}
 	}

@ -972,29 +983,24 @@ mod tests {

 	#[test]
 	fn test_bloom_filter_simple() {
-		let genesis = "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".from_hex().unwrap();
-
-		// block b1 (child of genesis)
-		let b1 = "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".from_hex().unwrap();
-
-		// block b2 (child of b1)
-		let b2 = "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".from_hex().unwrap();
-
-		// prepare for fork (b1a, child of genesis)
-		let b1a = "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".from_hex().unwrap();
-
-		// fork (b2a, child of b1a, with higher total difficulty)
-		let b2a = "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".from_hex().unwrap();
-
-		// fork back :)
-		let b3 = "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".from_hex().unwrap();
-
+		// TODO: From here
 		let bloom_b1 = H2048::from_str("00000020000000000000000000000000000000000000000002000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000040000000000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008000400000000000000000000002000").unwrap();

 		let bloom_b2 = H2048::from_str("00000000000000000000000000000000000000000000020000001000000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000008000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();

 		let bloom_ba = H2048::from_str("00000000000000000000000000000000000000000000020000000800000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000008000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();

+		let mut canon_chain = ChainGenerator::default();
+		let mut finalizer = BlockFinalizer::default();
+		let genesis = canon_chain.generate(&mut finalizer).unwrap();
+		let mut fork = canon_chain.fork(1);
+		let mut fork_finalizer = finalizer.fork();
+		let b1 = fork.with_bloom(bloom_b1.clone()).generate(&mut fork_finalizer).unwrap();
+		let b2 = fork.with_bloom(bloom_b2.clone()).generate(&mut fork_finalizer).unwrap();
+		let b3 = fork.with_bloom(bloom_ba.clone()).generate(&mut fork_finalizer).unwrap();
+		let b1a = canon_chain.with_bloom(bloom_ba.clone()).generate(&mut finalizer).unwrap();
+		let b2a = canon_chain.with_bloom(bloom_ba.clone()).generate(&mut finalizer).unwrap();
+
 		let temp = RandomTempPath::new();
 		let bc = BlockChain::new(BlockChainConfig::default(), &genesis, temp.as_path());

--- a/ethcore/src/blockchain/bloom_indexer.rs
+++ b/ethcore/src/blockchain/bloom_indexer.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/>.

-use util::hash::H256;
+use util::numbers::H256;
 use chainfilter::BloomIndex;

 /// Represents location of block bloom in extras database.
--- a/ethcore/src/blockchain/generator/block.rs
+++ b/ethcore/src/blockchain/generator/block.rs
@ -0,0 +1,64 @@
+// 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 util::rlp::*;
+use util::{H256, H2048};
+use util::U256;
+use util::bytes::Bytes;
+use header::Header;
+use transaction::SignedTransaction;
+
+use super::fork::Forkable;
+use super::bloom::WithBloom;
+use super::complete::CompleteBlock;
+
+/// Helper structure, used for encoding blocks.
+#[derive(Default)]
+pub struct Block {
+	pub header: Header,
+	pub transactions: Vec<SignedTransaction>,
+	pub uncles: Vec<Header>
+}
+
+impl Encodable for Block {
+	fn rlp_append(&self, s: &mut RlpStream) {
+		s.begin_list(3);
+		s.append(&self.header);
+		s.append(&self.transactions);
+		s.append(&self.uncles);
+	}
+}
+
+impl Forkable for Block {
+	fn fork(mut self, fork_number: usize) -> Self where Self: Sized {
+		self.header.difficulty = self.header.difficulty - U256::from(fork_number);
+		self
+	}
+}
+
+impl WithBloom for Block {
+	fn with_bloom(mut self, bloom: H2048) -> Self where Self: Sized {
+		self.header.log_bloom = bloom;
+		self
+	}
+}
+
+impl CompleteBlock for Block {
+	fn complete(mut self, parent_hash: H256) -> Bytes {
+		self.header.parent_hash = parent_hash;
+		encode(&self).to_vec()
+	}
+}
--- a/ethcore/src/blockchain/generator/bloom.rs
+++ b/ethcore/src/blockchain/generator/bloom.rs
@ -0,0 +1,35 @@
+// 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 util::hash::H2048;
+
+pub trait WithBloom {
+	fn with_bloom(self, bloom: H2048) -> Self where Self: Sized;
+}
+
+pub struct Bloom<'a, I> where I: 'a {
+	pub iter: &'a mut I,
+	pub bloom: H2048,
+}
+
+impl<'a, I> Iterator for Bloom<'a, I> where I: Iterator, <I as Iterator>::Item: WithBloom {
+	type Item = <I as Iterator>::Item;
+
+	#[inline]
+	fn next(&mut self) -> Option<Self::Item> {
+		self.iter.next().map(|item| item.with_bloom(self.bloom.clone()))
+	}
+}
--- a/ethcore/src/blockchain/generator/complete.rs
+++ b/ethcore/src/blockchain/generator/complete.rs
@ -0,0 +1,53 @@
+// 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 util::hash::H256;
+use util::bytes::Bytes;
+use util::sha3::Hashable;
+use views::BlockView;
+
+#[derive(Default, Clone)]
+pub struct BlockFinalizer {
+	parent_hash: H256
+}
+
+impl BlockFinalizer {
+	pub fn fork(&self) -> Self {
+		self.clone()
+	}
+}
+
+pub trait CompleteBlock {
+	fn complete(self, parent_hash: H256) -> Bytes;
+}
+
+pub struct Complete<'a, I> where I: 'a {
+	pub iter: &'a mut I,
+	pub finalizer: &'a mut BlockFinalizer,
+}
+
+impl<'a, I> Iterator for Complete<'a, I> where I: Iterator, <I as Iterator>::Item: CompleteBlock {
+	type Item = Bytes;
+
+	#[inline]
+	fn next(&mut self) -> Option<Self::Item> {
+		self.iter.next().map(|item| {
+			let rlp = item.complete(self.finalizer.parent_hash.clone());
+			self.finalizer.parent_hash = BlockView::new(&rlp).header_view().sha3();
+			rlp
+		})
+	}
+}
--- a/ethcore/src/blockchain/generator/fork.rs
+++ b/ethcore/src/blockchain/generator/fork.rs
@ -0,0 +1,42 @@
+// 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 trait Forkable {
+	fn fork(self, fork_number: usize) -> Self where Self: Sized;
+}
+
+pub struct Fork<I> {
+	pub iter: I,
+	pub fork_number: usize,
+}
+
+impl<I> Clone for Fork<I> where I: Iterator + Clone {
+	fn clone(&self) -> Self {
+		Fork {
+			iter: self.iter.clone(),
+			fork_number: self.fork_number
+		}
+	}
+}
+
+impl<I> Iterator for Fork<I> where I: Iterator, <I as Iterator>::Item: Forkable {
+	type Item = <I as Iterator>::Item;
+
+	#[inline]
+	fn next(&mut self) -> Option<Self::Item> {
+		self.iter.next().map(|item| item.fork(self.fork_number))
+	}
+}
--- a/ethcore/src/blockchain/generator/generator.rs
+++ b/ethcore/src/blockchain/generator/generator.rs
@ -0,0 +1,169 @@
+// 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 util::hash::H2048;
+use util::numbers::U256;
+use util::bytes::Bytes;
+use header::BlockNumber;
+use super::fork::Fork;
+use super::bloom::Bloom;
+use super::complete::{BlockFinalizer, CompleteBlock, Complete};
+use super::block::Block;
+
+/// Chain iterator interface.
+pub trait ChainIterator: Iterator + Sized {
+	/// Should be called to create a fork of current iterator.
+	/// Blocks generated by fork will have lower difficulty than current chain.
+	fn fork(&self, fork_number: usize) -> Fork<Self> where Self: Clone;
+	/// Should be called to make every consecutive block have given bloom.
+	fn with_bloom<'a>(&'a mut self, bloom: H2048) -> Bloom<'a, Self>;
+	/// Should be called to complete block. Without complete, block may have incorrect hash.
+	fn complete<'a>(&'a mut self, finalizer: &'a mut BlockFinalizer) -> Complete<'a, Self>;
+	/// Completes and generates block.
+	fn generate<'a>(&'a mut self, finalizer: &'a mut BlockFinalizer) -> Option<Bytes> where Self::Item: CompleteBlock;
+}
+
+impl<I> ChainIterator for I where I: Iterator + Sized {
+	fn fork(&self, fork_number: usize) -> Fork<Self> where I: Clone {
+		Fork {
+			iter: self.clone(),
+			fork_number: fork_number
+		}
+	}
+
+	fn with_bloom<'a>(&'a mut self, bloom: H2048) -> Bloom<'a, Self> {
+		Bloom {
+			iter: self,
+			bloom: bloom
+		}
+	}
+
+	fn complete<'a>(&'a mut self, finalizer: &'a mut BlockFinalizer) -> Complete<'a, Self> {
+		Complete {
+			iter: self,
+			finalizer: finalizer
+		}
+	}
+
+	fn generate<'a>(&'a mut self, finalizer: &'a mut BlockFinalizer) -> Option<Bytes> where <I as Iterator>::Item: CompleteBlock {
+		self.complete(finalizer).next()
+	}
+}
+
+/// Blockchain generator.
+#[derive(Clone)]
+pub struct ChainGenerator {
+	/// Next block number.
+	number: BlockNumber,
+	/// Next block difficulty.
+	difficulty: U256,
+}
+
+impl ChainGenerator {
+	fn prepare_block(&self) -> Block {
+		let mut block = Block::default();
+		block.header.number = self.number;
+		block.header.difficulty = self.difficulty;
+		block
+	}
+}
+
+impl Default for ChainGenerator {
+	fn default() -> Self {
+		ChainGenerator {
+			number: 0,
+			difficulty: U256::from(1000),
+		}
+	}
+}
+
+impl Iterator for ChainGenerator {
+	type Item = Block;
+
+	fn next(&mut self) -> Option<Self::Item> {
+		let block = self.prepare_block();
+		self.number += 1;
+		Some(block)
+	}
+}
+
+mod tests {
+	use util::hash::{H256, H2048};
+	use util::sha3::Hashable;
+	use views::BlockView;
+	use blockchain::generator::{ChainIterator, ChainGenerator, BlockFinalizer};
+
+	#[test]
+	fn canon_chain_generator() {
+		let mut canon_chain = ChainGenerator::default();
+		let mut finalizer = BlockFinalizer::default();
+
+		let genesis_rlp = canon_chain.generate(&mut finalizer).unwrap();
+		let genesis = BlockView::new(&genesis_rlp);
+
+		assert_eq!(genesis.header_view().parent_hash(), H256::default());
+		assert_eq!(genesis.header_view().number(), 0);
+
+		let b1_rlp = canon_chain.generate(&mut finalizer).unwrap();
+		let b1 = BlockView::new(&b1_rlp);
+
+		assert_eq!(b1.header_view().parent_hash(), genesis.header_view().sha3());
+		assert_eq!(b1.header_view().number(), 1);
+
+		let mut fork_chain = canon_chain.fork(1);
+
+		let b2_rlp_fork = fork_chain.generate(&mut finalizer.fork()).unwrap();
+		let b2_fork = BlockView::new(&b2_rlp_fork);
+
+		assert_eq!(b2_fork.header_view().parent_hash(), b1.header_view().sha3());
+		assert_eq!(b2_fork.header_view().number(), 2);
+
+		let b2_rlp = canon_chain.generate(&mut finalizer).unwrap();
+		let b2 = BlockView::new(&b2_rlp);
+
+		assert_eq!(b2.header_view().parent_hash(), b1.header_view().sha3());
+		assert_eq!(b2.header_view().number(), 2);
+		assert!(b2.header_view().difficulty() > b2_fork.header_view().difficulty());
+	}
+
+	#[test]
+	fn with_bloom_generator() {
+		let bloom = H2048([0x1; 256]);
+		let mut gen = ChainGenerator::default();
+		let mut finalizer = BlockFinalizer::default();
+
+		let block0_rlp = gen.with_bloom(bloom).generate(&mut finalizer).unwrap();
+		let block1_rlp = gen.generate(&mut finalizer).unwrap();
+		let block0 = BlockView::new(&block0_rlp);
+		let block1 = BlockView::new(&block1_rlp);
+
+		assert_eq!(block0.header_view().number(), 0);
+		assert_eq!(block0.header_view().parent_hash(), H256::default());
+
+		assert_eq!(block1.header_view().number(), 1);
+		assert_eq!(block1.header_view().parent_hash(), block0.header_view().sha3());
+
+	}
+
+	#[test]
+	fn generate_1000_blocks() {
+		let generator = ChainGenerator::default();
+		let mut finalizer = BlockFinalizer::default();
+		let blocks: Vec<_> = generator.take(1000).complete(&mut finalizer).collect();
+		assert_eq!(blocks.len(), 1000);
+	}
+}
+
--- a/ethcore/src/blockchain/generator/mod.rs
+++ b/ethcore/src/blockchain/generator/mod.rs
@ -14,4 +14,11 @@
 // 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 generators;
+mod bloom;
+mod block;
+mod complete;
+mod fork;
+pub mod generator;
+
+pub use self::complete::BlockFinalizer;
+pub use self::generator::{ChainIterator, ChainGenerator};
--- a/ethcore/src/blockchain/helpers/generators.rs
+++ b/ethcore/src/blockchain/helpers/generators.rs
@ -1,154 +0,0 @@
-// 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 util::rlp::*;
-use util::hash::{H256, H2048};
-use util::uint::{U256};
-use util::bytes::Bytes;
-use header::{BlockNumber, Header};
-use transaction::SignedTransaction;
-
-/// Chain iterator interface.
-pub trait ChainIterator: Iterator {
-	/// Should be called to create a fork of current iterator.
-	/// Blocks generated by fork will have lower difficulty than current chain.
-	fn fork(&mut self) -> Self;
-	/// Should be called to create new block with given bloom.
-	fn next_with_bloom(&mut self, bloom: H2048) -> Option<Self::Item>;
-}
-
-/// Helper structure, used for encoding blocks.
-#[derive(Default)]
-struct Block {
-	header: Header,
-	transactions: Vec<SignedTransaction>,
-	uncles: Vec<Header>
-}
-
-impl Encodable for Block {
-	fn rlp_append(&self, s: &mut RlpStream) {
-		s.begin_list(3);
-		s.append(&self.header);
-		s.append(&self.transactions);
-		s.append(&self.uncles);
-	}
-}
-
-/// Blockchain generator.
-pub struct ChainGenerator {
-	/// Next block number.
-	number: BlockNumber,
-	/// Next block parent hash.
-	parent_hash: H256,
-	/// Next block difficulty.
-	difficulty: U256,
-	/// Number of forks of current block.
-	number_of_forks: usize,
-}
-
-impl ChainGenerator {
-	fn prepare_block(&self) -> Block {
-		let mut block = Block::default();
-		block.header.parent_hash = self.parent_hash.clone();
-		block.header.number = self.number;
-		block.header.difficulty = self.difficulty;
-		block
-	}
-}
-
-impl Default for ChainGenerator {
-	fn default() -> Self {
-		ChainGenerator {
-			number: 0,
-			parent_hash: H256::default(),
-			difficulty: U256::from(1000),
-			number_of_forks: 0
-		}
-	}
-}
-
-impl Iterator for ChainGenerator {
-	type Item = Bytes;
-
-	fn next(&mut self) -> Option<Self::Item> {
-		let block = self.prepare_block();
-		self.number += 1;
-		self.parent_hash = block.header.hash();
-		self.number_of_forks = 0;
-		Some(encode(&block).to_vec())
-	}
-}
-
-impl ChainIterator for ChainGenerator {
-	fn fork(&mut self) -> Self {
-		self.number_of_forks += 1;
-		ChainGenerator {
-			number: self.number,
-			parent_hash: self.parent_hash.clone(),
-			difficulty: self.difficulty - U256::from(self.number_of_forks),
-			number_of_forks: 0
-		}
-	}
-
-	fn next_with_bloom(&mut self, bloom: H2048) -> Option<Self::Item> {
-		let mut block = self.prepare_block();
-		block.header.log_bloom = bloom;
-		self.number += 1;
-		self.parent_hash = block.header.hash();
-		self.number_of_forks = 0;
-		Some(encode(&block).to_vec())
-	}
-}
-
-#[cfg(test)]
-mod tests {
-	use util::hash::H256;
-	use util::sha3::Hashable;
-	use views::BlockView;
-	use super::{ChainIterator, ChainGenerator};
-
-	#[test]
-	fn canon_chain_generator() {
-		let mut canon_chain = ChainGenerator::default();
-
-		let genesis_rlp = canon_chain.next().unwrap();
-		let genesis = BlockView::new(&genesis_rlp);
-
-		assert_eq!(genesis.header_view().parent_hash(), H256::default());
-		assert_eq!(genesis.header_view().number(), 0);
-
-		let b1_rlp = canon_chain.next().unwrap();
-		let b1 = BlockView::new(&b1_rlp);
-
-		assert_eq!(b1.header_view().parent_hash(), genesis.header_view().sha3());
-		assert_eq!(b1.header_view().number(), 1);
-
-		let mut fork_chain = canon_chain.fork();
-
-		let b2_rlp_fork = fork_chain.next().unwrap();
-		let b2_fork = BlockView::new(&b2_rlp_fork);
-
-		assert_eq!(b2_fork.header_view().parent_hash(), b1.header_view().sha3());
-		assert_eq!(b2_fork.header_view().number(), 2);
-
-		let b2_rlp = canon_chain.next().unwrap();
-		let b2 = BlockView::new(&b2_rlp);
-
-		assert_eq!(b2.header_view().parent_hash(), b1.header_view().sha3());
-		assert_eq!(b2.header_view().number(), 2);
-		assert!(b2.header_view().difficulty() > b2_fork.header_view().difficulty());
-	}
-}
--- a/ethcore/src/blockchain/mod.rs
+++ b/ethcore/src/blockchain/mod.rs
@ -24,7 +24,7 @@ mod cache;
 mod tree_route;
 mod update;
 #[cfg(test)]
-mod helpers;
+mod generator;

 pub use self::blockchain::{BlockProvider, BlockChain, BlockChainConfig};
 pub use self::cache::CacheSize;
--- a/ethcore/src/blockchain/tree_route.rs
+++ b/ethcore/src/blockchain/tree_route.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/>.

-use util::hash::H256;
+use util::numbers::H256;

 /// Represents a tree route between `from` block and `to` block:
 #[derive(Debug)]
--- a/ethcore/src/blockchain/update.rs
+++ b/ethcore/src/blockchain/update.rs
@ -1,5 +1,5 @@
 use std::collections::HashMap;
-use util::hash::H256;
+use util::numbers::H256;
 use header::BlockNumber;
 use blockchain::block_info::BlockInfo;
 use extras::{BlockDetails, BlockReceipts, TransactionAddress, BlocksBlooms};
--- a/ethcore/src/chainfilter/chainfilter.rs
+++ b/ethcore/src/chainfilter/chainfilter.rs
@ -88,7 +88,7 @@ impl<'a, D> ChainFilter<'a, D> where D: FilterDataSource
 			None => return None,
 			Some(level_bloom) => match level {
 				// if we are on the lowest level
-				0 => return match offset < to_block {
+				0 => return match offset <= to_block {
 					// take the value if its smaller than to_block
 					true if level_bloom.contains(bloom) => Some(vec![offset]),
 					// return None if it is is equal to to_block
--- a/ethcore/src/chainfilter/tests.rs
+++ b/ethcore/src/chainfilter/tests.rs
@ -81,13 +81,13 @@ fn test_topic_basic_search() {

 	{
 		let filter = ChainFilter::new(&cache, index_size, bloom_levels);
-		let blocks = filter.blocks_with_bloom(&to_bloom(&topic), 0, 23);
+		let blocks = filter.blocks_with_bloom(&to_bloom(&topic), 0, 22);
 		assert_eq!(blocks.len(), 0);
 	}

 	{
 		let filter = ChainFilter::new(&cache, index_size, bloom_levels);
-		let blocks = filter.blocks_with_bloom(&to_bloom(&topic), 23, 24);
+		let blocks = filter.blocks_with_bloom(&to_bloom(&topic), 23, 23);
 		assert_eq!(blocks.len(), 1);
 		assert_eq!(blocks[0], 23);
 	}
@ -235,11 +235,11 @@ fn test_chainfilter_real_data_short_searches() {
 	for_each_log(include_bytes!("logs.txt"), | block_number, address, topics | {
 		println!("block_number: {:?}", block_number);
 		let filter = ChainFilter::new(&cache, index_size, bloom_levels);
-		let blocks = filter.blocks_with_bloom(&to_bloom(address), block_number, block_number + 1);
+		let blocks = filter.blocks_with_bloom(&to_bloom(address), block_number, block_number);
 		assert_eq!(blocks.len(), 1);
 		for (i, topic) in topics.iter().enumerate() {
 			println!("topic: {:?}", i);
-			let blocks = filter.blocks_with_bloom(&to_bloom(topic), block_number, block_number + 1);
+			let blocks = filter.blocks_with_bloom(&to_bloom(topic), block_number, block_number);
 			assert_eq!(blocks.len(), 1);
 		}
 	});
--- a/ethcore/src/client.rs
+++ b/ethcore/src/client.rs
@ -21,7 +21,7 @@ use util::panics::*;
 use blockchain::{BlockChain, BlockProvider};
 use views::BlockView;
 use error::*;
-use header::{BlockNumber, Header};
+use header::{BlockNumber};
 use state::State;
 use spec::Spec;
 use engine::Engine;
@ -179,7 +179,7 @@ pub struct ClientReport {

 impl ClientReport {
 	/// Alter internal reporting to reflect the additional `block` has been processed.
-	pub fn accrue_block(&mut self, block: &PreVerifiedBlock) {
+	pub fn accrue_block(&mut self, block: &PreverifiedBlock) {
 		self.blocks_imported += 1;
 		self.transactions_applied += block.transactions.len();
 		self.gas_processed = self.gas_processed + block.header.gas_used;
@ -196,6 +196,11 @@ pub struct Client {
 	report: RwLock<ClientReport>,
 	import_lock: Mutex<()>,
 	panic_handler: Arc<PanicHandler>,
+
+	// for sealing...
+	sealing_block: Mutex<Option<ClosedBlock>>,
+	author: RwLock<Address>,
+	extra_data: RwLock<Bytes>,
 }

 const HISTORY: u64 = 1000;
@ -231,7 +236,10 @@ impl Client {
 			block_queue: RwLock::new(block_queue),
 			report: RwLock::new(Default::default()),
 			import_lock: Mutex::new(()),
-			panic_handler: panic_handler
+			panic_handler: panic_handler,
+			sealing_block: Mutex::new(None),
+			author: RwLock::new(Address::new()),
+			extra_data: RwLock::new(Vec::new()),
 		}))
 	}

@ -240,10 +248,10 @@ impl Client {
 		self.block_queue.write().unwrap().flush();
 	}

-	fn build_last_hashes(&self, header: &Header) -> LastHashes {
+	fn build_last_hashes(&self, parent_hash: H256) -> LastHashes {
 		let mut last_hashes = LastHashes::new();
 		last_hashes.resize(256, H256::new());
-		last_hashes[0] = header.parent_hash.clone();
+		last_hashes[0] = parent_hash;
 		let chain = self.chain.read().unwrap();
 		for i in 0..255 {
 			match chain.block_details(&last_hashes[i]) {
@ -256,10 +264,17 @@ impl Client {
 		last_hashes
 	}

-	fn check_and_close_block(&self, block: &PreVerifiedBlock) -> Result<ClosedBlock, ()> {
+	fn check_and_close_block(&self, block: &PreverifiedBlock) -> Result<ClosedBlock, ()> {
 		let engine = self.engine.deref().deref();
 		let header = &block.header;

+		// Check the block isn't so old we won't be able to enact it.
+		let best_block_number = self.chain.read().unwrap().best_block_number();
+		if best_block_number >= HISTORY && header.number() <= best_block_number - HISTORY {
+			warn!(target: "client", "Block import failed for #{} ({})\nBlock is ancient (current best block: #{}).", header.number(), header.hash(), best_block_number);
+			return Err(());
+		}
+
 		// Verify Block Family
 		let verify_family_result = verify_block_family(&header, &block.bytes, engine, self.chain.read().unwrap().deref());
 		if let Err(e) = verify_family_result {
@ -276,7 +291,7 @@ impl Client {

 		// Enact Verified Block
 		let parent = chain_has_parent.unwrap();
-		let last_hashes = self.build_last_hashes(header);
+		let last_hashes = self.build_last_hashes(header.parent_hash.clone());
 		let db = self.state_db.lock().unwrap().clone();

 		let enact_result = enact_verified(&block, engine, db, &parent, last_hashes);
@ -305,6 +320,8 @@ impl Client {
 		let _import_lock = self.import_lock.lock();
 		let blocks = self.block_queue.write().unwrap().drain(max_blocks_to_import);

+		let original_best = self.chain_info().best_block_hash;
+
 		for block in blocks {
 			let header = &block.header;

@ -360,6 +377,10 @@ impl Client {
 			}
 		}

+		if self.chain_info().best_block_hash != original_best {
+			self.prepare_sealing();
+		}
+
 		imported
 	}

@ -406,8 +427,82 @@ impl Client {
 			BlockId::Latest => Some(self.chain.read().unwrap().best_block_number())
 		}
 	}
+
+	/// Get the author that we will seal blocks as.
+	pub fn author(&self) -> Address {
+		self.author.read().unwrap().clone()
+	}
+
+	/// Set the author that we will seal blocks as.
+	pub fn set_author(&self, author: Address) {
+		*self.author.write().unwrap() = author;
+	}
+
+	/// Get the extra_data that we will seal blocks wuth.
+	pub fn extra_data(&self) -> Bytes {
+		self.extra_data.read().unwrap().clone()
+	}
+
+	/// Set the extra_data that we will seal blocks with.
+	pub fn set_extra_data(&self, extra_data: Bytes) {
+		*self.extra_data.write().unwrap() = extra_data;
+	}
+
+	/// New chain head event. Restart mining operation.
+	pub fn prepare_sealing(&self) {
+		let h = self.chain.read().unwrap().best_block_hash();
+		let mut b = OpenBlock::new(
+			self.engine.deref().deref(),
+			self.state_db.lock().unwrap().clone(),
+			match self.chain.read().unwrap().block_header(&h) { Some(ref x) => x, None => {return;} },
+			self.build_last_hashes(h.clone()),
+			self.author(),
+			self.extra_data()
+		);
+
+		self.chain.read().unwrap().find_uncle_headers(&h).into_iter().foreach(|h| { b.push_uncle(h).unwrap(); });
+
+		// TODO: push transactions.
+
+		let b = b.close();
+		trace!("Sealing: number={}, hash={}, diff={}", b.hash(), b.block().header().difficulty(), b.block().header().number());
+		*self.sealing_block.lock().unwrap() = Some(b);
+	}
+
+	/// Grab the `ClosedBlock` that we want to be sealed. Comes as a mutex that you have to lock.
+	pub fn sealing_block(&self) -> &Mutex<Option<ClosedBlock>> {
+		if self.sealing_block.lock().unwrap().is_none() {
+			self.prepare_sealing();
+		}
+		&self.sealing_block
+	}
+
+	/// Submit `seal` as a valid solution for the header of `pow_hash`.
+	/// Will check the seal, but not actually insert the block into the chain.
+	pub fn submit_seal(&self, pow_hash: H256, seal: Vec<Bytes>) -> Result<(), Error> {
+		let mut maybe_b = self.sealing_block.lock().unwrap();
+		match *maybe_b {
+			Some(ref b) if b.hash() == pow_hash => {}
+			_ => { return Err(Error::PowHashInvalid); }
+		}
+
+		let b = maybe_b.take();
+		match b.unwrap().try_seal(self.engine.deref().deref(), seal) {
+			Err(old) => {
+				*maybe_b = Some(old);
+				Err(Error::PowInvalid)
+			}
+			Ok(sealed) => {
+				// TODO: commit DB from `sealed.drain` and make a VerifiedBlock to skip running the transactions twice.
+				try!(self.import_block(sealed.rlp_bytes()));
+				Ok(())
+			}
+		}
+	}
 }

+// TODO: need MinerService MinerIoHandler
+
 impl BlockChainClient for Client {
 	fn block_header(&self, id: BlockId) -> Option<Bytes> {
 		let chain = self.chain.read().unwrap();
@ -484,12 +579,14 @@ impl BlockChainClient for Client {
 	}

 	fn import_block(&self, bytes: Bytes) -> ImportResult {
-		let header = BlockView::new(&bytes).header();
-		if self.chain.read().unwrap().is_known(&header.hash()) {
-			return Err(ImportError::AlreadyInChain);
+		{
+			let header = BlockView::new(&bytes).header_view();
+			if self.chain.read().unwrap().is_known(&header.sha3()) {
+				return Err(x!(ImportError::AlreadyInChain));
+			}
+			if self.block_status(BlockId::Hash(header.parent_hash())) == BlockStatus::Unknown {
+				return Err(x!(BlockError::UnknownParent(header.parent_hash())));
 			}
-		if self.block_status(BlockId::Hash(header.parent_hash)) == BlockStatus::Unknown {
-			return Err(ImportError::UnknownParent);
 		}
 		self.block_queue.write().unwrap().import_block(bytes)
 	}
--- a/ethcore/src/engine.rs
+++ b/ethcore/src/engine.rs
@ -30,8 +30,6 @@ pub trait Engine : Sync + Send {

 	/// The number of additional header fields required for this engine.
 	fn seal_fields(&self) -> usize { 0 }
-	/// Default values of the additional fields RLP-encoded in a raw (non-list) harness.
-	fn seal_rlp(&self) -> Bytes { vec![] }

 	/// Additional engine-specific information for the user/developer concerning `header`.
 	fn extra_info(&self, _header: &Header) -> HashMap<String, String> { HashMap::new() }
@ -76,9 +74,20 @@ pub trait Engine : Sync + Send {
 	/// Verify a particular transaction is valid.
 	fn verify_transaction(&self, _t: &SignedTransaction, _header: &Header) -> Result<(), Error> { Ok(()) }

-	/// Don't forget to call Super::populateFromParent when subclassing & overriding.
+	/// Verify the seal of a block. This is an auxilliary method that actually just calls other `verify_` methods
+	/// to get the job done. By default it must pass `verify_basic` and `verify_block_unordered`. If more or fewer
+	/// methods are needed for an Engine, this may be overridden.
+	fn verify_block_seal(&self, header: &Header) -> Result<(), Error> {
+		self.verify_block_basic(header, None).and_then(|_| self.verify_block_unordered(header, None))
+	}
+
+	/// Don't forget to call Super::populate_from_parent when subclassing & overriding.
 	// TODO: consider including State in the params.
-	fn populate_from_parent(&self, _header: &mut Header, _parent: &Header) {}
+	fn populate_from_parent(&self, header: &mut Header, parent: &Header) {
+		header.difficulty = parent.difficulty;
+		header.gas_limit = parent.gas_limit;
+		header.note_dirty();
+	}

 	// TODO: builtin contract routing - to do this properly, it will require removing the built-in configuration-reading logic
 	// from Spec into here and removing the Spec::builtins field.
--- a/ethcore/src/error.rs
+++ b/ethcore/src/error.rs
@ -131,25 +131,14 @@ pub enum BlockError {
 #[derive(Debug)]
 /// Import to the block queue result
 pub enum ImportError {
-	/// Bad block detected
-	Bad(Option<Error>),
-	/// Already in the block chain
+	/// Already in the block chain.
 	AlreadyInChain,
-	/// Already in the block queue
+	/// Already in the block queue.
 	AlreadyQueued,
-	/// Unknown parent
-	UnknownParent,
+	/// Already marked as bad from a previous import (could mean parent is bad).
+	KnownBad,
 }

-impl From<Error> for ImportError {
-	fn from(err: Error) -> ImportError {
-		ImportError::Bad(Some(err))
-	}
-}
-
-/// Result of import block operation.
-pub type ImportResult = Result<H256, ImportError>;
-
 #[derive(Debug)]
 /// General error type which should be capable of representing all errors in ethcore.
 pub enum Error {
@ -163,14 +152,29 @@ pub enum Error {
 	Execution(ExecutionError),
 	/// Error concerning transaction processing.
 	Transaction(TransactionError),
+	/// Error concerning block import.
+	Import(ImportError),
+	/// PoW hash is invalid or out of date.
+	PowHashInvalid,
+	/// The value of the nonce or mishash is invalid.
+	PowInvalid,
 }

+/// Result of import block operation.
+pub type ImportResult = Result<H256, Error>;
+
 impl From<TransactionError> for Error {
 	fn from(err: TransactionError) -> Error {
 		Error::Transaction(err)
 	}
 }

+impl From<ImportError> for Error {
+	fn from(err: ImportError) -> Error {
+		Error::Import(err)
+	}
+}
+
 impl From<BlockError> for Error {
 	fn from(err: BlockError) -> Error {
 		Error::Block(err)
--- a/ethcore/src/ethereum/ethash.rs
+++ b/ethcore/src/ethereum/ethash.rs
@ -74,8 +74,6 @@ impl Engine for Ethash {
 	fn version(&self) -> SemanticVersion { SemanticVersion::new(1, 0, 0) }
 	// Two fields - mix
 	fn seal_fields(&self) -> usize { 2 }
-	// Two empty data items in RLP.
-	fn seal_rlp(&self) -> Bytes { encode(&H64::new()).to_vec() }

 	/// Additional engine-specific information for the user/developer concerning `header`.
 	fn extra_info(&self, _header: &Header) -> HashMap<String, String> { HashMap::new() }
@ -106,7 +104,7 @@ impl Engine for Ethash {
 				max(gas_floor_target, gas_limit - gas_limit / bound_divisor + x!(1) + (header.gas_used * x!(6) / x!(5)) / bound_divisor)
 			}
 		};
-
+		header.note_dirty();
 //		info!("ethash: populate_from_parent #{}: difficulty={} and gas_limit={}", header.number, header.difficulty, header.gas_limit);
 	}

@ -146,7 +144,8 @@ impl Engine for Ethash {
 		let difficulty = Ethash::boundary_to_difficulty(&Ethash::from_ethash(quick_get_difficulty(
 			&Ethash::to_ethash(header.bare_hash()),
 			header.nonce().low_u64(),
-				&Ethash::to_ethash(header.mix_hash()))));
+			&Ethash::to_ethash(header.mix_hash())
+		)));
 		if difficulty < header.difficulty {
 			return Err(From::from(BlockError::InvalidProofOfWork(OutOfBounds { min: Some(header.difficulty), max: None, found: difficulty })));
 		}
@ -241,10 +240,21 @@ impl Ethash {
 		target
 	}

-	fn boundary_to_difficulty(boundary: &H256) -> U256 {
+	/// Convert an Ethash boundary to its original difficulty. Basically just `f(x) = 2^256 / x`.
+	pub fn boundary_to_difficulty(boundary: &H256) -> U256 {
 		U256::from((U512::one() << 256) / x!(U256::from(boundary.as_slice())))
 	}

+	/// Convert an Ethash difficulty to the target boundary. Basically just `f(x) = 2^256 / x`.
+	pub fn difficulty_to_boundary(difficulty: &U256) -> H256 {
+		x!(U256::from((U512::one() << 256) / x!(difficulty)))
+	}
+
+	/// Given the `block_number`, determine the seed hash for Ethash.
+	pub fn get_seedhash(number: BlockNumber) -> H256 {
+		Self::from_ethash(ethash::get_seedhash(number))
+	}
+
 	fn to_ethash(hash: H256) -> EH256 {
 		unsafe { mem::transmute(hash) }
 	}
@ -255,12 +265,20 @@ impl Ethash {
 }

 impl Header {
-	fn nonce(&self) -> H64 {
+	/// Get the none field of the header.
+	pub fn nonce(&self) -> H64 {
 		decode(&self.seal()[1])
 	}
-	fn mix_hash(&self) -> H256 {
+
+	/// Get the mix hash field of the header.
+	pub fn mix_hash(&self) -> H256 {
 		decode(&self.seal()[0])
 	}
+
+	/// Set the nonce and mix hash fields of the header.
+	pub fn set_nonce_and_mix_hash(&mut self, nonce: &H64, mix_hash: &H256) {
+		self.seal = vec![encode(mix_hash).to_vec(), encode(nonce).to_vec()];
+	}
 }

 #[cfg(test)]
--- a/ethcore/src/evm/ext.rs
+++ b/ethcore/src/evm/ext.rs
@ -16,9 +16,7 @@

 //! Interface for Evm externalities.

-use common::Bytes;
-use util::hash::*;
-use util::uint::*;
+use util::common::*;
 use evm::{Schedule, Error};
 use env_info::*;

--- a/ethcore/src/header.rs
+++ b/ethcore/src/header.rs
@ -102,10 +102,12 @@ impl Header {
 		Self::default()
 	}

-	/// Get the number field of the header.
-	pub fn number(&self) -> BlockNumber { self.number }
+	/// Get the parent_hash field of the header.
+	pub fn parent_hash(&self) -> &H256 { &self.parent_hash }
 	/// Get the timestamp field of the header.
 	pub fn timestamp(&self) -> u64 { self.timestamp }
+	/// Get the number field of the header.
+	pub fn number(&self) -> BlockNumber { self.number }
 	/// Get the author field of the header.
 	pub fn author(&self) -> &Address { &self.author }

@ -127,11 +129,13 @@ impl Header {
 	// TODO: seal_at, set_seal_at &c.

 	/// Set the number field of the header.
-	pub fn set_number(&mut self, a: BlockNumber) { self.number = a; self.note_dirty(); }
+	pub fn set_parent_hash(&mut self, a: H256) { self.parent_hash = a; self.note_dirty(); }
 	/// Set the timestamp field of the header.
 	pub fn set_timestamp(&mut self, a: u64) { self.timestamp = a; self.note_dirty(); }
 	/// Set the timestamp field of the header to the current time.
-	pub fn set_timestamp_now(&mut self) { self.timestamp = now_utc().to_timespec().sec as u64; self.note_dirty(); }
+	pub fn set_timestamp_now(&mut self, but_later_than: u64) { self.timestamp = max(now_utc().to_timespec().sec as u64, but_later_than + 1); self.note_dirty(); }
+	/// Set the number field of the header.
+	pub fn set_number(&mut self, a: BlockNumber) { self.number = a; self.note_dirty(); }
 	/// Set the author field of the header.
 	pub fn set_author(&mut self, a: Address) { if a != self.author { self.author = a; self.note_dirty(); } }

--- a/ethcore/src/json_tests/state.rs
+++ b/ethcore/src/json_tests/state.rs
@ -115,7 +115,7 @@ declare_test!{StateTests_stSolidityTest, "StateTests/stSolidityTest"}
 declare_test!{StateTests_stSpecialTest, "StateTests/stSpecialTest"}
 declare_test!{StateTests_stSystemOperationsTest, "StateTests/stSystemOperationsTest"}
 declare_test!{StateTests_stTransactionTest, "StateTests/stTransactionTest"}
-//declare_test!{StateTests_stTransitionTest, "StateTests/stTransitionTest"}
+declare_test!{StateTests_stTransitionTest, "StateTests/stTransitionTest"}
 declare_test!{StateTests_stWalletTest, "StateTests/stWalletTest"}


--- a/ethcore/src/state.rs
+++ b/ethcore/src/state.rs
@ -335,10 +335,9 @@ impl fmt::Debug for State {
 mod tests {

 use super::*;
-use util::hash::*;
+use util::common::*;
 use util::trie::*;
 use util::rlp::*;
-use util::uint::*;
 use account::*;
 use tests::helpers::*;
 use devtools::*;
--- a/ethcore/src/tests/client.rs
+++ b/ethcore/src/tests/client.rs
@ -15,6 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

 use client::{BlockChainClient, Client, ClientConfig, BlockId};
+use block::IsBlock;
 use tests::helpers::*;
 use common::*;
 use devtools::*;
@ -106,3 +107,22 @@ fn can_collect_garbage() {
 	client.tick();
 	assert!(client.blockchain_cache_info().blocks < 100 * 1024);
 }
+
+#[test]
+fn can_mine() {
+	let dummy_blocks = get_good_dummy_block_seq(2);
+	let client_result = get_test_client_with_blocks(vec![dummy_blocks[0].clone()]);
+	let client = client_result.reference();
+	let b = client.sealing_block();
+	let pow_hash = {
+		let u = b.lock().unwrap();
+		match *u {
+			Some(ref b) => {
+				assert_eq!(*b.block().header().parent_hash(), BlockView::new(&dummy_blocks[0]).header_view().sha3());
+				b.hash()
+			}
+			None => { panic!(); }
+		}	
+	};
+	assert!(client.submit_seal(pow_hash, vec![]).is_ok());
+}
--- a/ethcore/src/transaction.rs
+++ b/ethcore/src/transaction.rs
@ -100,10 +100,10 @@ impl FromJson for SignedTransaction {
 				v: match json.find("v") { Some(ref j) => u16::from_json(j) as u8, None => 0 },
 				r: match json.find("r") { Some(j) => xjson!(j), None => x!(0) },
 				s: match json.find("s") { Some(j) => xjson!(j), None => x!(0) },
-				hash: RefCell::new(None),
+				hash: Cell::new(None),
 				sender: match json.find("sender") {
-					Some(&Json::String(ref sender)) => RefCell::new(Some(address_from_hex(clean(sender)))),
-					_ => RefCell::new(None),
+					Some(&Json::String(ref sender)) => Cell::new(Some(address_from_hex(clean(sender)))),
+					_ => Cell::new(None),
 				}
 			}
 		}
@ -127,8 +127,8 @@ impl Transaction {
 			r: r,
 			s: s,
 			v: v + 27,
-			hash: RefCell::new(None),
-			sender: RefCell::new(None)
+			hash: Cell::new(None),
+			sender: Cell::new(None),
 		}
 	}

@ -140,8 +140,8 @@ impl Transaction {
 			r: U256::zero(),
 			s: U256::zero(),
 			v: 0,
-			hash: RefCell::new(None),
-			sender: RefCell::new(None)
+			hash: Cell::new(None),
+			sender: Cell::new(None),
 		}
 	}

@ -171,9 +171,9 @@ pub struct SignedTransaction {
 	/// The S field of the signature; helps describe the point on the curve.
 	s: U256,
 	/// Cached hash.
-	hash: RefCell<Option<H256>>,
+	hash: Cell<Option<H256>>,
 	/// Cached sender.
-	sender: RefCell<Option<Address>>
+	sender: Cell<Option<Address>>,
 }

 impl PartialEq for SignedTransaction {
@ -208,8 +208,8 @@ impl Decodable for SignedTransaction {
 			v: try!(d.val_at(6)),
 			r: try!(d.val_at(7)),
 			s: try!(d.val_at(8)),
-			hash: RefCell::new(None),
-			sender: RefCell::new(None),
+			hash: Cell::new(None),
+			sender: Cell::new(None),
 		})
 	}
 }
@ -238,12 +238,13 @@ impl SignedTransaction {

 	/// Get the hash of this header (sha3 of the RLP).
 	pub fn hash(&self) -> H256 {
- 		let mut hash = self.hash.borrow_mut();
- 		match &mut *hash {
- 			&mut Some(ref h) => h.clone(),
- 			hash @ &mut None => {
- 				*hash = Some(self.rlp_sha3());
- 				hash.as_ref().unwrap().clone()
+		let hash = self.hash.get();
+		match hash {
+			Some(h) => h,
+			None => {
+				let h = self.rlp_sha3();
+				self.hash.set(Some(h));
+				h
 			}
 		}
 	}
@ -265,12 +266,13 @@ impl SignedTransaction {

 	/// Returns transaction sender.
 	pub fn sender(&self) -> Result<Address, Error> {
- 		let mut sender = self.sender.borrow_mut();
- 		match &mut *sender {
- 			&mut Some(ref h) => Ok(h.clone()),
- 			sender @ &mut None => {
- 				*sender = Some(From::from(try!(ec::recover(&self.signature(), &self.unsigned.hash())).sha3()));
- 				Ok(sender.as_ref().unwrap().clone())
+		let sender = self.sender.get();
+		match sender {
+			Some(s) => Ok(s),
+			None => {
+				let s = Address::from(try!(ec::recover(&self.signature(), &self.unsigned.hash())).sha3());
+				self.sender.set(Some(s));
+				Ok(s)
 			}
 		}
 	}
--- a/ethcore/src/verification.rs
+++ b/ethcore/src/verification.rs
@ -26,7 +26,7 @@ use engine::Engine;
 use blockchain::*;

 /// Preprocessed block data gathered in `verify_block_unordered` call
-pub struct PreVerifiedBlock {
+pub struct PreverifiedBlock {
 	/// Populated block header
 	pub header: Header,
 	/// Populated block transactions
@ -55,8 +55,8 @@ pub fn verify_block_basic(header: &Header, bytes: &[u8], engine: &Engine) -> Res

 /// Phase 2 verification. Perform costly checks such as transaction signatures and block nonce for ethash.
 /// Still operates on a individual block
-/// Returns a PreVerifiedBlock structure populated with transactions
-pub fn verify_block_unordered(header: Header, bytes: Bytes, engine: &Engine) -> Result<PreVerifiedBlock, Error> {
+/// Returns a PreverifiedBlock structure populated with transactions
+pub fn verify_block_unordered(header: Header, bytes: Bytes, engine: &Engine) -> Result<PreverifiedBlock, Error> {
 	try!(engine.verify_block_unordered(&header, Some(&bytes)));
 	for u in Rlp::new(&bytes).at(2).iter().map(|rlp| rlp.as_val::<Header>()) {
 		try!(engine.verify_block_unordered(&u, None));
@ -70,7 +70,7 @@ pub fn verify_block_unordered(header: Header, bytes: Bytes, engine: &Engine) ->
 			transactions.push(t);
 		}
 	}
-	Ok(PreVerifiedBlock {
+	Ok(PreverifiedBlock {
 		header: header,
 		transactions: transactions,
 		bytes: bytes,
--- a/install-deps.sh
+++ b/install-deps.sh
@ -569,7 +569,7 @@ function run_installer()
 			if [[ $isSudo == false ]]; then
 				apt-get install -q -y sudo
 			fi
-			curl -sf https://raw.githubusercontent.com/brson/multirust/master/blastoff.sh | sudo sh -s -- --yes
+			curl -sf https://raw.githubusercontent.com/brson/multirust/master/quick-install.sh | sudo sh -s -- --yes
 			echo
 		fi

--- a/parity/main.rs
+++ b/parity/main.rs
@ -85,6 +85,10 @@ Options:
  --jsonrpc-url URL        Specify URL for JSON-RPC API server [default: 127.0.0.1:8545].
  --jsonrpc-cors URL       Specify CORS header for JSON-RPC API responses [default: null].

+  --author ADDRESS         Specify the block author (aka "coinbase") address for sending block rewards
+                           from sealed blocks [default: 0037a6b811ffeb6e072da21179d11b1406371c63].
+  --extra-data STRING      Specify a custom extra-data for authored blocks, no more than 32 characters.
+
  -l --logging LOGGING     Specify the logging level.
  -v --version             Show information about version.
  -h --help                Show this screen.
@ -114,6 +118,8 @@ struct Args {
 	flag_jsonrpc_cors: String,
 	flag_logging: Option<String>,
 	flag_version: bool,
+	flag_author: String,
+	flag_extra_data: Option<String>,
 }

 fn setup_log(init: &Option<String>) {
@ -196,6 +202,18 @@ impl Configuration {
 		self.args.flag_db_path.replace("$HOME", env::home_dir().unwrap().to_str().unwrap())
 	}

+	fn author(&self) -> Address {
+		Address::from_str(&self.args.flag_author).unwrap_or_else(|_| die!("{}: Invalid address for --author. Must be 40 hex characters, without the 0x at the beginning.", self.args.flag_author))
+	}
+
+	fn extra_data(&self) -> Bytes {
+		match self.args.flag_extra_data {
+			Some(ref x) if x.len() <= 32 => x.as_bytes().to_owned(),
+			None => version_data(),
+			Some(ref x) => { die!("{}: Extra data must be at most 32 characters.", x); }
+		}
+	}
+
 	fn _keys_path(&self) -> String {
 		self.args.flag_keys_path.replace("$HOME", env::home_dir().unwrap().to_str().unwrap())
 	}
@ -296,6 +314,8 @@ impl Configuration {
 		client_config.queue.max_mem_use = self.args.flag_queue_max_size;
 		let mut service = ClientService::start(client_config, spec, net_settings, &Path::new(&self.path())).unwrap();
 		let client = service.client().clone();
+		client.set_author(self.author());
+		client.set_extra_data(self.extra_data());

 		// Sync
 		let sync = EthSync::register(service.network(), sync_config, client);
@ -354,7 +374,6 @@ impl Default for Informant {
 }

 impl Informant {
-
 	fn format_bytes(b: usize) -> String {
 		match binary_prefix(b as f64) {
 			Standalone(bytes)   => format!("{} bytes", bytes),
--- a/rpc/Cargo.toml
+++ b/rpc/Cargo.toml
@ -9,12 +9,14 @@ build = "build.rs"
 [lib]

 [dependencies]
+log = "0.3"
 serde = "0.7.0"
 serde_json = "0.7.0"
 jsonrpc-core = "1.2"
 jsonrpc-http-server = "2.1"
 ethcore-util = { path = "../util" }
 ethcore = { path = "../ethcore" }
+ethash = { path = "../ethash" }
 ethsync = { path = "../sync" }
 clippy = { version = "0.0.44", optional = true }
 rustc-serialize = "0.3"
--- a/rpc/src/v1/impls/eth.rs
+++ b/rpc/src/v1/impls/eth.rs
@ -15,14 +15,17 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

 //! Eth rpc implementation.
-use std::sync::{Arc, Weak};
 use ethsync::{EthSync, SyncState};
 use jsonrpc_core::*;
-use util::hash::*;
-use util::uint::*;
+use util::numbers::*;
 use util::sha3::*;
+use util::standard::{RwLock, HashMap, Arc, Weak};
+use util::rlp::encode;
 use ethcore::client::*;
+use ethcore::block::{IsBlock};
 use ethcore::views::*;
+//#[macro_use] extern crate log;
+use ethcore::ethereum::Ethash;
 use ethcore::ethereum::denominations::shannon;
 use v1::traits::{Eth, EthFilter};
 use v1::types::{Block, BlockTransactions, BlockNumber, Bytes, SyncStatus, SyncInfo, Transaction, OptionalValue, Index, Filter, Log};
@ -30,7 +33,8 @@ use v1::types::{Block, BlockTransactions, BlockNumber, Bytes, SyncStatus, SyncIn
 /// Eth rpc implementation.
 pub struct EthClient {
 	client: Weak<Client>,
-	sync: Weak<EthSync>
+	sync: Weak<EthSync>,
+	hashrates: RwLock<HashMap<H256, u64>>,
 }

 impl EthClient {
@ -38,7 +42,8 @@ impl EthClient {
 	pub fn new(client: &Arc<Client>, sync: &Arc<EthSync>) -> Self {
 		EthClient {
 			client: Arc::downgrade(client),
-			sync: Arc::downgrade(sync)
+			sync: Arc::downgrade(sync),
+			hashrates: RwLock::new(HashMap::new()),
 		}
 	}

@ -125,7 +130,7 @@ impl Eth for EthClient {
 	// TODO: return real value of mining once it's implemented.
 	fn is_mining(&self, params: Params) -> Result<Value, Error> {
 		match params {
-			Params::None => Ok(Value::Bool(false)),
+			Params::None => to_value(&!self.hashrates.read().unwrap().is_empty()),
 			_ => Err(Error::invalid_params())
 		}
 	}
@ -133,7 +138,7 @@ impl Eth for EthClient {
 	// TODO: return real hashrate once we have mining
 	fn hashrate(&self, params: Params) -> Result<Value, Error> {
 		match params {
-			Params::None => to_value(&U256::zero()),
+			Params::None => to_value(&self.hashrates.read().unwrap().iter().fold(0u64, |sum, (_, v)| sum + v)),
 			_ => Err(Error::invalid_params())
 		}
 	}
@ -220,6 +225,43 @@ impl Eth for EthClient {
 				to_value(&logs)
 			})
 	}
+
+	fn work(&self, params: Params) -> Result<Value, Error> {
+		match params {
+			Params::None => {
+				let c = take_weak!(self.client);
+				let u = c.sealing_block().lock().unwrap();
+				match *u {
+					Some(ref b) => {
+						let pow_hash = b.hash();
+						let target = Ethash::difficulty_to_boundary(b.block().header().difficulty());
+						let seed_hash = Ethash::get_seedhash(b.block().header().number());
+						to_value(&(pow_hash, seed_hash, target))
+					}
+					_ => Err(Error::invalid_params())
+				}
+			},
+			_ => Err(Error::invalid_params())
+		}
+	}
+
+	fn submit_work(&self, params: Params) -> Result<Value, Error> {
+		from_params::<(H64, H256, H256)>(params).and_then(|(nonce, pow_hash, mix_hash)| {
+//			trace!("Decoded: nonce={}, pow_hash={}, mix_hash={}", nonce, pow_hash, mix_hash);
+			let c = take_weak!(self.client);
+			let seal = vec![encode(&mix_hash).to_vec(), encode(&nonce).to_vec()];
+			let r = c.submit_seal(pow_hash, seal);
+			to_value(&r.is_ok())
+		})
+	}
+
+	fn submit_hashrate(&self, params: Params) -> Result<Value, Error> {
+		// TODO: Index should be U256.
+		from_params::<(Index, H256)>(params).and_then(|(rate, id)| {
+			self.hashrates.write().unwrap().insert(id, rate.value() as u64);
+			to_value(&true)
+		})
+	}
 }

 /// Eth filter rpc implementation.
--- a/rpc/src/v1/impls/web3.rs
+++ b/rpc/src/v1/impls/web3.rs
@ -31,7 +31,7 @@ impl Web3 for Web3Client {
 	fn client_version(&self, params: Params) -> Result<Value, Error> {
 		match params {
 			Params::None => {
-				Ok(Value::String(version())),
+				Ok(Value::String(version().to_owned().replace("Parity/", "Parity//"))),
 			}
 			_ => Err(Error::invalid_params())
 		}
--- a/rpc/src/v1/types/block.rs
+++ b/rpc/src/v1/types/block.rs
@ -15,8 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

 use serde::{Serialize, Serializer};
-use util::hash::*;
-use util::uint::*;
+use util::numbers::*;
 use v1::types::{Bytes, Transaction, OptionalValue};

 #[derive(Debug)]
@ -71,8 +70,7 @@ pub struct Block {
 #[cfg(test)]
 mod tests {
 	use serde_json;
-	use util::hash::*;
-	use util::uint::*;
+	use util::numbers::*;
 	use v1::types::{Transaction, Bytes, OptionalValue};
 	use super::*;

--- a/rpc/src/v1/types/filter.rs
+++ b/rpc/src/v1/types/filter.rs
@ -17,7 +17,7 @@
 use serde::{Deserialize, Deserializer, Error};
 use serde_json::value;
 use jsonrpc_core::Value;
-use util::hash::*;
+use util::numbers::*;
 use v1::types::BlockNumber;
 use ethcore::filter::Filter as EthFilter;
 use ethcore::client::BlockId;
--- a/rpc/src/v1/types/log.rs
+++ b/rpc/src/v1/types/log.rs
@ -14,8 +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/>.

-use util::hash::*;
-use util::uint::*;
+use util::numbers::*;
 use ethcore::log_entry::LocalizedLogEntry;
 use v1::types::Bytes;

@ -55,8 +54,7 @@ impl From<LocalizedLogEntry> for Log {
 mod tests {
 	use serde_json;
 	use std::str::FromStr;
-	use util::hash::*;
-	use util::uint::*;
+	use util::numbers::*;
 	use v1::types::{Bytes, Log};

 	#[test]
--- a/rpc/src/v1/types/sync.rs
+++ b/rpc/src/v1/types/sync.rs
@ -15,7 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

 use serde::{Serialize, Serializer};
-use util::uint::*;
+use util::numbers::*;

 #[derive(Default, Debug, Serialize, PartialEq)]
 pub struct SyncInfo {
--- a/rpc/src/v1/types/transaction.rs
+++ b/rpc/src/v1/types/transaction.rs
@ -14,8 +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/>.

-use util::hash::*;
-use util::uint::*;
+use util::numbers::*;
 use ethcore::transaction::{LocalizedTransaction, Action};
 use v1::types::{Bytes, OptionalValue};

--- a/sync/src/chain.rs
+++ b/sync/src/chain.rs
@ -487,19 +487,19 @@ impl ChainSync {
 		// TODO: Decompose block and add to self.headers and self.bodies instead
 		if header.number == From::from(self.current_base_block() + 1) {
 			match io.chain().import_block(block_rlp.as_raw().to_vec()) {
-				Err(ImportError::AlreadyInChain) => {
+				Err(Error::Import(ImportError::AlreadyInChain)) => {
 					trace!(target: "sync", "New block already in chain {:?}", h);
 				},
-				Err(ImportError::AlreadyQueued) => {
+				Err(Error::Import(ImportError::AlreadyQueued)) => {
 					trace!(target: "sync", "New block already queued {:?}", h);
 				},
 				Ok(_) => {
 					self.last_imported_block = Some(header.number);
 					trace!(target: "sync", "New block queued {:?}", h);
 				},
-				Err(ImportError::UnknownParent) => {
+				Err(Error::Block(BlockError::UnknownParent(p))) => {
 					unknown = true;
-					trace!(target: "sync", "New block with unknown parent {:?}", h);
+					trace!(target: "sync", "New block with unknown parent ({:?}) {:?}", p, h);
 				},
 				Err(e) => {
 					debug!(target: "sync", "Bad new block {:?} : {:?}", h, e);
@ -645,16 +645,7 @@ impl ChainSync {
 		match self.last_imported_block { None => 0, Some(x) => x }
 	}

-	/// Find some headers or blocks to download for a peer.
-	fn request_blocks(&mut self, io: &mut SyncIo, peer_id: PeerId, ignore_others: bool) {
-		self.clear_peer_download(peer_id);
-
-		if io.chain().queue_info().is_full() {
-			self.pause_sync();
-			return;
-		}
-
-		// check to see if we need to download any block bodies first
+	fn find_block_bodies_hashes_to_request(&self, ignore_others: bool) -> (Vec<H256>, Vec<BlockNumber>) {
 		let mut needed_bodies: Vec<H256> = Vec::new();
 		let mut needed_numbers: Vec<BlockNumber> = Vec::new();

@ -674,18 +665,33 @@ impl ChainSync {
 				}
 			}
 		}
+		(needed_bodies, needed_numbers)
+	}
+
+	/// Find some headers or blocks to download for a peer.
+	fn request_blocks(&mut self, io: &mut SyncIo, peer_id: PeerId, ignore_others: bool) {
+		self.clear_peer_download(peer_id);
+
+		if io.chain().queue_info().is_full() {
+			self.pause_sync();
+			return;
+		}
+
+		// check to see if we need to download any block bodies first
+		let (needed_bodies, needed_numbers) = self.find_block_bodies_hashes_to_request(ignore_others);
 		if !needed_bodies.is_empty() {
 			let (head, _) = self.headers.range_iter().next().unwrap();
 			if needed_numbers.first().unwrap() - head > self.max_download_ahead_blocks as BlockNumber {
 				trace!(target: "sync", "{}: Stalled download ({} vs {}), helping with downloading block bodies", peer_id, needed_numbers.first().unwrap(), head);
 				self.request_blocks(io, peer_id, true);
-				return;
-			}
+			} else {
 				self.downloading_bodies.extend(needed_numbers.iter());
 				replace(&mut self.peers.get_mut(&peer_id).unwrap().asking_blocks, needed_numbers);
 				self.request_bodies(io, peer_id, needed_bodies);
 			}
-		else {
+			return;
+		}
+
 		// check if need to download headers
 		let mut start = 0;
 		if !self.have_common_block {
@ -743,7 +749,6 @@ impl ChainSync {
 			self.request_headers_by_number(io, peer_id, start, 1, 0, false);
 		}
 	}
-	}

 	/// Clear all blocks/headers marked as being downloaded by a peer.
 	fn clear_peer_download(&mut self, peer_id: PeerId) {
@ -791,12 +796,12 @@ impl ChainSync {
 				}

 				match io.chain().import_block(block_rlp.out()) {
-					Err(ImportError::AlreadyInChain) => {
+					Err(Error::Import(ImportError::AlreadyInChain)) => {
 						trace!(target: "sync", "Block already in chain {:?}", h);
 						self.last_imported_block = Some(headers.0 + i as BlockNumber);
 						self.last_imported_hash = Some(h.clone());
 					},
-					Err(ImportError::AlreadyQueued) => {
+					Err(Error::Import(ImportError::AlreadyQueued)) => {
 						trace!(target: "sync", "Block already queued {:?}", h);
 						self.last_imported_block = Some(headers.0 + i as BlockNumber);
 						self.last_imported_hash = Some(h.clone());
@ -1189,8 +1194,8 @@ impl ChainSync {
 			.collect::<Vec<_>>()
 	}

-	/// propagades latest block to lagging peers
-	fn propagade_blocks(&mut self, local_best: &H256, best_number: BlockNumber, io: &mut SyncIo) -> usize {
+	/// propagates latest block to lagging peers
+	fn propagate_blocks(&mut self, local_best: &H256, best_number: BlockNumber, io: &mut SyncIo) -> usize {
 		let updated_peers = {
 			let lagging_peers = self.get_lagging_peers(io);

@ -1216,8 +1221,8 @@ impl ChainSync {
 		sent
 	}

-	/// propagades new known hashes to all peers
-	fn propagade_new_hashes(&mut self, local_best: &H256, best_number: BlockNumber, io: &mut SyncIo) -> usize {
+	/// propagates new known hashes to all peers
+	fn propagate_new_hashes(&mut self, local_best: &H256, best_number: BlockNumber, io: &mut SyncIo) -> usize {
 		let updated_peers = self.get_lagging_peers(io);
 		let mut sent = 0;
 		let last_parent = HeaderView::new(&io.chain().block_header(BlockId::Hash(local_best.clone())).unwrap()).parent_hash();
@ -1252,8 +1257,8 @@ impl ChainSync {
 	pub fn chain_blocks_verified(&mut self, io: &mut SyncIo) {
 		let chain = io.chain().chain_info();
 		if (((chain.best_block_number as i64) - (self.last_send_block_number as i64)).abs() as BlockNumber) < MAX_PEER_LAG_PROPAGATION {
-			let blocks = self.propagade_blocks(&chain.best_block_hash, chain.best_block_number, io);
-			let hashes = self.propagade_new_hashes(&chain.best_block_hash, chain.best_block_number, io);
+			let blocks = self.propagate_blocks(&chain.best_block_hash, chain.best_block_number, io);
+			let hashes = self.propagate_new_hashes(&chain.best_block_hash, chain.best_block_number, io);
 			if blocks != 0 || hashes != 0 {
 				trace!(target: "sync", "Sent latest {} blocks and {} hashes to peers.", blocks, hashes);
 			}
@ -1277,7 +1282,8 @@ impl ChainSync {

 		good.for_each(|txs| {
 			let mut transaction_queue = self.transaction_queue.lock().unwrap();
-			transaction_queue.remove_all(&txs);
+			let hashes = txs.iter().map(|tx| tx.hash()).collect::<Vec<H256>>();
+			transaction_queue.remove_all(&hashes);
 		});
 		bad.for_each(|txs| {
 			// populate sender
@ -1465,7 +1471,7 @@ mod tests {
 		let best_number = client.chain_info().best_block_number;
 		let mut io = TestIo::new(&mut client, &mut queue, None);

-		let peer_count = sync.propagade_new_hashes(&best_hash, best_number, &mut io);
+		let peer_count = sync.propagate_new_hashes(&best_hash, best_number, &mut io);

 		// 1 message should be send
 		assert_eq!(1, io.queue.len());
@ -1485,7 +1491,7 @@ mod tests {
 		let best_number = client.chain_info().best_block_number;
 		let mut io = TestIo::new(&mut client, &mut queue, None);

-		let peer_count = sync.propagade_blocks(&best_hash, best_number, &mut io);
+		let peer_count = sync.propagate_blocks(&best_hash, best_number, &mut io);

 		// 1 message should be send
 		assert_eq!(1, io.queue.len());
@ -1591,7 +1597,7 @@ mod tests {
 		let best_number = client.chain_info().best_block_number;
 		let mut io = TestIo::new(&mut client, &mut queue, None);

-		sync.propagade_new_hashes(&best_hash, best_number, &mut io);
+		sync.propagate_new_hashes(&best_hash, best_number, &mut io);

 		let data = &io.queue[0].data.clone();
 		let result = sync.on_peer_new_hashes(&mut io, 0, &UntrustedRlp::new(&data));
@ -1610,7 +1616,7 @@ mod tests {
 		let best_number = client.chain_info().best_block_number;
 		let mut io = TestIo::new(&mut client, &mut queue, None);

-		sync.propagade_blocks(&best_hash, best_number, &mut io);
+		sync.propagate_blocks(&best_hash, best_number, &mut io);

 		let data = &io.queue[0].data.clone();
 		let result = sync.on_peer_new_block(&mut io, 0, &UntrustedRlp::new(&data));
--- a/sync/src/tests/chain.rs
+++ b/sync/src/tests/chain.rs
@ -122,7 +122,7 @@ fn status_packet() {
 }

 #[test]
-fn propagade_hashes() {
+fn propagate_hashes() {
 	let mut net = TestNet::new(6);
 	net.peer_mut(1).chain.add_blocks(10, BlocksWith::Uncle);
 	net.sync();
@ -148,7 +148,7 @@ fn propagade_hashes() {
 }

 #[test]
-fn propagade_blocks() {
+fn propagate_blocks() {
 	let mut net = TestNet::new(2);
 	net.peer_mut(1).chain.add_blocks(10, BlocksWith::Uncle);
 	net.sync();
--- a/sync/src/transaction_queue.rs
+++ b/sync/src/transaction_queue.rs
@ -18,121 +18,126 @@

 //! Transaction Queue

-use std::vec::Vec;
 use std::cmp::{Ordering};
 use std::collections::{HashMap, BTreeSet};
-use util::uint::{Uint, U256};
-use util::hash::{Address};
+use util::numbers::{Uint, U256};
+use util::hash::{Address, H256};
 use util::table::*;
 use ethcore::transaction::*;


 #[derive(Clone, Debug)]
-struct VerifiedTransaction {
-	tx: SignedTransaction,
-	nonce_height: U256
+struct TransactionOrder {
+	nonce_height: U256,
+	gas_price: U256,
+	hash: H256,
 }

-impl VerifiedTransaction {
-	pub fn new(tx: SignedTransaction, nonce_height: U256) -> VerifiedTransaction {
-		VerifiedTransaction {
-			tx: tx,
-			nonce_height: nonce_height
+impl TransactionOrder {
+	pub fn for_transaction(tx: &VerifiedTransaction, base_nonce: U256) -> Self {
+		TransactionOrder {
+			nonce_height: tx.nonce() - base_nonce,
+			gas_price: tx.transaction.gas_price,
+			hash: tx.hash(),
 		}
 	}
-
-	pub fn sender(&self) -> Address {
-		self.tx.sender().unwrap()
-	}
 }

-impl Eq for VerifiedTransaction {}
-impl PartialEq for VerifiedTransaction {
-	fn eq(&self, other: &VerifiedTransaction) -> bool {
+impl Eq for TransactionOrder {}
+impl PartialEq for TransactionOrder {
+	fn eq(&self, other: &TransactionOrder) -> bool {
 		self.cmp(other) == Ordering::Equal
 	}
 }
-impl PartialOrd for VerifiedTransaction {
-	fn partial_cmp(&self, other: &VerifiedTransaction) -> Option<Ordering> {
+impl PartialOrd for TransactionOrder {
+	fn partial_cmp(&self, other: &TransactionOrder) -> Option<Ordering> {
 		Some(self.cmp(other))
 	}
 }
-impl Ord for VerifiedTransaction {
-	fn cmp(&self, b: &VerifiedTransaction) -> Ordering {
+impl Ord for TransactionOrder {
+	fn cmp(&self, b: &TransactionOrder) -> Ordering {
 		// First check nonce_height
 		if self.nonce_height != b.nonce_height {
 			return self.nonce_height.cmp(&b.nonce_height);
 		}

 		// Then compare gas_prices
-		let a_gas = self.tx.gas_price;
-		let b_gas = b.tx.gas_price;
+		let a_gas = self.gas_price;
+		let b_gas = b.gas_price;
 		if a_gas != b_gas {
 			return a_gas.cmp(&b_gas);
 		}

-		// Compare nonce
-		let a_nonce = self.tx.nonce;
-		let b_nonce = b.tx.nonce;
-		if a_nonce != b_nonce {
-			return a_nonce.cmp(&b_nonce);
-		}
-
-		// and senders
-		let a_sender = self.sender();
-		let b_sender = b.sender();
-		a_sender.cmp(&b_sender)
+		// Compare hashes
+		self.hash.cmp(&b.hash)
 	}
 }

-struct TransactionsByPriorityAndAddress {
-	priority: BTreeSet<VerifiedTransaction>,
-	address: Table<Address, U256, VerifiedTransaction>,
+struct VerifiedTransaction {
+	transaction: SignedTransaction
+}
+impl VerifiedTransaction {
+	fn new(transaction: SignedTransaction) -> Self {
+		VerifiedTransaction {
+			transaction: transaction
+		}
+	}
+
+	fn hash(&self) -> H256 {
+		self.transaction.hash()
+	}
+
+	fn nonce(&self) -> U256 {
+		self.transaction.nonce
+	}
+
+	fn sender(&self) -> Address {
+		self.transaction.sender().unwrap()
+	}
+}
+
+struct TransactionSet {
+	by_priority: BTreeSet<TransactionOrder>,
+	by_address: Table<Address, U256, TransactionOrder>,
 	limit: usize,
 }

-impl TransactionsByPriorityAndAddress {
-	fn insert(&mut self, address: Address, nonce: U256, verified_tx: VerifiedTransaction) {
-		self.priority.insert(verified_tx.clone());
-		self.address.insert(address, nonce, verified_tx);
+impl TransactionSet {
+	fn insert(&mut self, sender: Address, nonce: U256, order: TransactionOrder) {
+		self.by_priority.insert(order.clone());
+		self.by_address.insert(sender, nonce, order);
 	}

-	fn enforce_limit(&mut self) {
-		let len = self.priority.len();
+	fn enforce_limit(&mut self, by_hash: &HashMap<H256, VerifiedTransaction>) {
+		let len = self.by_priority.len();
 		if len <= self.limit {
 			return;
 		}

-		let to_remove : Vec<SignedTransaction> = {
-			self.priority
+		let to_drop : Vec<&VerifiedTransaction> = {
+			self.by_priority
 				.iter()
 				.skip(self.limit)
-				.map(|v_tx| v_tx.tx.clone())
+				.map(|order| by_hash.get(&order.hash).expect("Inconsistency in queue detected."))
 				.collect()
 		};

-		for tx in to_remove {
-			self.remove(&tx);
+		for tx in to_drop {
+			self.drop(&tx.sender(), &tx.nonce());
 		}
 	}

-	fn remove_by_address(&mut self, sender: &Address, nonce: &U256) -> Option<VerifiedTransaction> {
-		if let Some(verified_tx) = self.address.remove(sender, nonce) {
-			self.priority.remove(&verified_tx);
-			return Some(verified_tx);
+	fn drop(&mut self, sender: &Address, nonce: &U256) -> Option<TransactionOrder> {
+		if let Some(tx_order) = self.by_address.remove(sender, nonce) {
+			self.by_priority.remove(&tx_order);
+			return Some(tx_order);
 		}
 		None
 	}

-	fn remove(&mut self, tx: &SignedTransaction) -> Option<VerifiedTransaction> {
-		// First find the transaction by address
-		let address = tx.sender().unwrap();
-		self.remove_by_address(&address, &tx.nonce)
-	}
-
 	fn clear(&mut self) {
-		self.priority.clear();
-		self.address.clear();
+		self.by_priority.clear();
+		self.by_address.clear();
 	}
 }

@ -148,9 +153,11 @@ pub struct TransactionQueueStatus {
 /// TransactionQueue implementation
 pub struct TransactionQueue {
 	/// Priority queue for transactions that can go to block
-	current: TransactionsByPriorityAndAddress,
+	current: TransactionSet,
 	/// Priority queue for transactions that has been received but are not yet valid to go to block
-	future: TransactionsByPriorityAndAddress,
+	future: TransactionSet,
+	/// All transactions managed by queue indexed by hash
+	by_hash: HashMap<H256, VerifiedTransaction>,
 	/// Last nonce of transaction in current
 	last_nonces: HashMap<Address, U256>,
 	/// First nonce of transaction in current (used to determine priority)
@ -165,20 +172,21 @@ impl TransactionQueue {

 	/// Create new instance of this Queue with specified limits
 	pub fn with_limits(current_limit: usize, future_limit: usize) -> Self {
-		let current = TransactionsByPriorityAndAddress {
-			address: Table::new(),
-			priority: BTreeSet::new(),
+		let current = TransactionSet {
+			by_priority: BTreeSet::new(),
+			by_address: Table::new(),
 			limit: current_limit,
 		};
-		let future = TransactionsByPriorityAndAddress {
-			address: Table::new(),
-			priority: BTreeSet::new(),
+		let future = TransactionSet {
+			by_priority: BTreeSet::new(),
+			by_address: Table::new(),
 			limit: future_limit,
 		};

 		TransactionQueue {
 			current: current,
 			future: future,
+			by_hash: HashMap::new(),
 			last_nonces: HashMap::new(),
 			first_nonces: HashMap::new(),
 		}
@ -187,8 +195,8 @@ impl TransactionQueue {
 	/// Returns current status for this queue
 	pub fn status(&self) -> TransactionQueueStatus {
 		TransactionQueueStatus {
-			pending: self.current.priority.len(),
-			future: self.future.priority.len(),
+			pending: self.current.by_priority.len(),
+			future: self.future.by_priority.len(),
 		}
 	}

@ -203,29 +211,42 @@ impl TransactionQueue {
 	/// Add signed transaction to queue to be verified and imported
 	pub fn add<T>(&mut self, tx: SignedTransaction, fetch_nonce: &T)
 		where T: Fn(&Address) -> U256 {
-		self.import_tx(tx, fetch_nonce);
+		self.import_tx(VerifiedTransaction::new(tx), fetch_nonce);
 	}

-	/// Removes all transactions in given slice
+	/// Removes all transactions identified by hashes given in slice
 	///
 	/// If gap is introduced marks subsequent transactions as future
-	pub fn remove_all(&mut self, txs: &[SignedTransaction]) {
-		for tx in txs {
-			self.remove(&tx);
+	pub fn remove_all(&mut self, transaction_hashes: &[H256]) {
+		for transaction_hash in transaction_hashes {
+			self.remove(&transaction_hash);
 		}
 	}

-	/// Removes transaction from queue.
+	/// Removes transaction identified by hashes from queue.
 	///
 	/// If gap is introduced marks subsequent transactions as future
-	pub fn remove(&mut self, tx: &SignedTransaction) {
+	pub fn remove(&mut self, transaction_hash: &H256) {
+		let transaction = self.by_hash.remove(transaction_hash);
+		if transaction.is_none() {
+			// We don't know this transaction
+			return;
+		}
+		let transaction = transaction.unwrap();
+		let sender = transaction.sender();
+		let nonce = transaction.nonce();
+
+		// Remove from future
+		self.future.drop(&sender, &nonce);
+
 		// Remove from current
-		let removed = self.current.remove(tx);
-		if let Some(verified_tx) = removed {
-			let sender = verified_tx.sender();
+		let order = self.current.drop(&sender, &nonce);
+		if order.is_none() {
+			return;
+		}

 		// Are there any other transactions from this sender?
-			if !self.current.address.has_row(&sender) {
+		if !self.current.by_address.has_row(&sender) {
 			// Clear last & first nonces
 			self.last_nonces.remove(&sender);
 			self.first_nonces.remove(&sender);
@ -234,20 +255,19 @@ impl TransactionQueue {

 		// Let's find those with higher nonce (TODO [todr] optimize?)
 		let to_move_to_future = {
-				let row_map = self.current.address.row(&sender).unwrap();
-				let tx_nonce = verified_tx.tx.nonce;
+			let row_map = self.current.by_address.row(&sender).unwrap();
 			let mut to_future = Vec::new();
 			let mut highest = U256::zero();
-				let mut lowest = tx_nonce.clone();
+			let mut lowest = nonce.clone();

 			// Search nonces to remove and track lowest and highest
-				for (nonce, _) in row_map.iter() {
-					if nonce > &tx_nonce {
-						to_future.push(nonce.clone());
-					} else if nonce > &highest {
-						highest = nonce.clone();
-					} else if nonce < &lowest {
-						lowest = nonce.clone();
+			for (current_nonce, _) in row_map.iter() {
+				if current_nonce > &nonce {
+					to_future.push(current_nonce.clone());
+				} else if current_nonce > &highest {
+					highest = current_nonce.clone();
+				} else if current_nonce < &lowest {
+					lowest = current_nonce.clone();
 				}
 			}

@ -258,7 +278,7 @@ impl TransactionQueue {
 				self.last_nonces.insert(sender.clone(), highest);
 			}

-				if lowest == tx_nonce {
+			if lowest == nonce {
 				self.first_nonces.remove(&sender);
 			} else {
 				self.first_nonces.insert(sender.clone(), lowest);
@ -269,35 +289,29 @@ impl TransactionQueue {
 		};

 		for k in to_move_to_future {
-				if let Some(v) = self.current.remove_by_address(&sender, &k) {
-					self.future.insert(sender.clone(), v.tx.nonce, v);
-				}
-			}
-			self.future.enforce_limit();
-			return;
-		}
-
-		// Remove from future
-		{
-			let sender = tx.sender().unwrap();
-			if let Some(_) = self.future.remove_by_address(&sender, &tx.nonce) {
-				return;
+			if let Some(v) = self.current.drop(&sender, &k) {
+				// TODO [todr] Recalculate height?
+				self.future.insert(sender.clone(), k, v);
 			}
 		}
+		self.future.enforce_limit(&self.by_hash);
 	}

 	/// Returns top transactions from the queue
 	pub fn top_transactions(&self, size: usize) -> Vec<SignedTransaction> {
-		self.current.priority
+		self.current.by_priority
 			.iter()
 			.take(size)
-			.map(|t| t.tx.clone()).collect()
+			.map(|t| self.by_hash.get(&t.hash).expect("Transaction Queue Inconsistency"))
+			.map(|t| t.transaction.clone())
+			.collect()
 	}

 	/// Removes all elements (in any state) from the queue
 	pub fn clear(&mut self) {
 		self.current.clear();
 		self.future.clear();
+		self.by_hash.clear();
 		self.last_nonces.clear();
 		self.first_nonces.clear();
 	}
@ -305,31 +319,30 @@ impl TransactionQueue {
 	fn move_future_txs(&mut self, address: Address, current_nonce: U256, first_nonce: U256) -> Option<U256> {
 		let mut current_nonce = current_nonce + U256::one();
 		{
-			let txs_by_nonce = self.future.address.row_mut(&address);
-			if let None = txs_by_nonce {
+			let by_nonce = self.future.by_address.row_mut(&address);
+			if let None = by_nonce {
 				return None;
 			}
-			let mut txs_by_nonce = txs_by_nonce.unwrap();
-
-			while let Some(tx) = txs_by_nonce.remove(&current_nonce) {
-				// remove also from priority
-				self.future.priority.remove(&tx);
+			let mut by_nonce = by_nonce.unwrap();
+			while let Some(order) = by_nonce.remove(&current_nonce) {
+				// remove also from priority and hash
+				self.future.by_priority.remove(&order);
 				// Put to current
-				let height = current_nonce - first_nonce;
-				let verified_tx = VerifiedTransaction::new(tx.tx, U256::from(height));
-				self.current.insert(address.clone(), verified_tx.tx.nonce, verified_tx);
+				let transaction = self.by_hash.get(&order.hash).expect("TransactionQueue Inconsistency");
+				let order = TransactionOrder::for_transaction(transaction, first_nonce);
+				self.current.insert(address.clone(), transaction.nonce(), order);
 				current_nonce = current_nonce + U256::one();
 			}
 		}
-		self.future.address.clear_if_empty(&address);
+		self.future.by_address.clear_if_empty(&address);
 		// Returns last inserted nonce
 		Some(current_nonce - U256::one())
 	}

-	fn import_tx<T>(&mut self, tx: SignedTransaction, fetch_nonce: &T)
+	fn import_tx<T>(&mut self, tx: VerifiedTransaction, fetch_nonce: &T)
 		where T: Fn(&Address) -> U256 {
-		let nonce = tx.nonce;
-		let address = tx.sender().unwrap();
+		let nonce = tx.nonce();
+		let address = tx.sender();

 		let next_nonce = U256::one() + self.last_nonces
 			.get(&address)
@ -338,11 +351,12 @@ impl TransactionQueue {

 		// Check height
 		if nonce > next_nonce {
-			let height = nonce - next_nonce;
-			let verified_tx = VerifiedTransaction::new(tx, height);
+			let order = TransactionOrder::for_transaction(&tx, next_nonce);
+			// Insert to by_hash
+			self.by_hash.insert(tx.hash(), tx);
 			// We have a gap - put to future
-			self.future.insert(address, nonce, verified_tx);
-			self.future.enforce_limit();
+			self.future.insert(address, nonce, order);
+			self.future.enforce_limit(&self.by_hash);
 			return;
 		} else if next_nonce > nonce {
 			// Droping transaction
@ -355,29 +369,34 @@ impl TransactionQueue {
 			.cloned()
 			.unwrap_or_else(|| nonce.clone());

-		let height = nonce - first_nonce;
-		let verified_tx = VerifiedTransaction::new(tx, height);
+		let order = TransactionOrder::for_transaction(&tx, first_nonce);
+		// Insert to by_hash
+		self.by_hash.insert(tx.hash(), tx);
+
 		// Insert to current
-		self.current.insert(address.clone(), nonce, verified_tx);
+		self.current.insert(address.clone(), nonce, order);
 		// But maybe there are some more items waiting in future?
 		let new_last_nonce = self.move_future_txs(address.clone(), nonce, first_nonce);
 		self.first_nonces.insert(address.clone(), first_nonce);
 		self.last_nonces.insert(address.clone(), new_last_nonce.unwrap_or(nonce));
 		// Enforce limit
-		self.current.enforce_limit();
+		self.current.enforce_limit(&self.by_hash);
 	}
 }

+
 #[cfg(test)]
 mod test {
 	extern crate rustc_serialize;
 	use self::rustc_serialize::hex::FromHex;
-
+	use std::collections::{HashMap, BTreeSet};
 	use util::crypto::KeyPair;
-	use util::uint::{U256, Uint};
+	use util::numbers::{U256, Uint};
 	use util::hash::{Address};
+	use util::table::*;
 	use ethcore::transaction::*;
 	use super::*;
+	use super::{TransactionSet, TransactionOrder, VerifiedTransaction};

 	fn new_unsigned_tx(nonce: U256) -> Transaction {
 		Transaction {
@ -409,6 +428,46 @@ mod test {
 		(tx.sign(secret), tx2.sign(secret))
 	}

+	#[test]
+	fn should_create_transaction_set() {
+		// given
+		let mut set = TransactionSet {
+			by_priority: BTreeSet::new(),
+			by_address: Table::new(),
+			limit: 1
+		};
+		let (tx1, tx2) = new_txs(U256::from(1));
+		let tx1 = VerifiedTransaction::new(tx1);
+		let tx2 = VerifiedTransaction::new(tx2);
+		let by_hash = {
+			let mut x = HashMap::new();
+			let tx1 = VerifiedTransaction::new(tx1.transaction.clone());
+			let tx2 = VerifiedTransaction::new(tx2.transaction.clone());
+			x.insert(tx1.hash(), tx1);
+			x.insert(tx2.hash(), tx2);
+			x
+		};
+		// Insert both transactions
+		let order1 = TransactionOrder::for_transaction(&tx1, U256::zero());
+		set.insert(tx1.sender(), tx1.nonce(), order1.clone());
+		let order2 = TransactionOrder::for_transaction(&tx2, U256::zero());
+		set.insert(tx2.sender(), tx2.nonce(), order2.clone());
+		assert_eq!(set.by_priority.len(), 2);
+		assert_eq!(set.by_address.len(), 2);
+
+		// when
+		set.enforce_limit(&by_hash);
+
+		// then
+		assert_eq!(set.by_priority.len(), 1);
+		assert_eq!(set.by_address.len(), 1);
+		assert_eq!(set.by_priority.iter().next().unwrap().clone(), order1);
+		set.clear();
+		assert_eq!(set.by_priority.len(), 0);
+		assert_eq!(set.by_address.len(), 0);
+	}
+
+
 	#[test]
 	fn should_import_tx() {
 		// given
@ -496,8 +555,8 @@ mod test {
 		assert_eq!(txq2.status().future, 1);

 		// when
-		txq2.remove(&tx);
-		txq2.remove(&tx2);
+		txq2.remove(&tx.hash());
+		txq2.remove(&tx2.hash());


 		// then
@ -519,7 +578,7 @@ mod test {
 		assert_eq!(txq.status().pending, 3);

 		// when
-		txq.remove(&tx);
+		txq.remove(&tx.hash());

 		// then
 		let stats = txq.status();
@ -609,14 +668,15 @@ mod test {
 		assert_eq!(txq.status().pending, 2);

 		// when
-		txq.remove(&tx1);
+		txq.remove(&tx1.hash());
+		assert_eq!(txq.status().pending, 0);
 		assert_eq!(txq.status().future, 1);
 		txq.add(tx1.clone(), &default_nonce);

 		// then
 		let stats = txq.status();
-		assert_eq!(stats.pending, 2);
 		assert_eq!(stats.future, 0);
+		assert_eq!(stats.pending, 2);

 	}

--- a/util/Cargo.toml
+++ b/util/Cargo.toml
@ -35,6 +35,7 @@ ethcore-devtools = { path = "../devtools" }
 libc = "0.2.7"
 vergen = "0.1"
 target_info = "0.1"
+bigint = { path = "bigint" }

 [features]
 default = []
--- a/util/bigint/Cargo.toml
+++ b/util/bigint/Cargo.toml
@ -0,0 +1,23 @@
+[package]
+description = "Rust-assembler implementation of big integers arithmetic"
+homepage = "http://ethcore.io"
+license = "GPL-3.0"
+name = "bigint"
+version = "0.1.0"
+authors = ["Ethcore <admin@ethcore.io>"]
+build = "build.rs"
+
+[build-dependencies]
+rustc_version = "0.1"
+
+[dependencies]
+rustc-serialize = "0.3"
+arrayvec = "0.3"
+rand = "0.3.12"
+serde = "0.7.0"
+clippy = { version = "0.0.44", optional = true }
+heapsize = "0.3"
+
+[features]
+x64asm_arithmetic=[]
+rust_arithmetic=[]
--- a/util/bigint/build.rs
+++ b/util/bigint/build.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/>.
+
+extern crate rustc_version;
+
+use rustc_version::{version_meta, Channel};
+
+fn main() {
+	if let Channel::Nightly = version_meta().channel {
+		println!("cargo:rustc-cfg=asm_available");
+	}
+}
--- a/util/bigint/src/lib.rs
+++ b/util/bigint/src/lib.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/>.
+
+#![cfg_attr(asm_available, feature(asm))]
+
+extern crate rustc_serialize;
+extern crate serde;
+#[macro_use] extern crate heapsize;
+
+pub mod uint;
--- a/util/bigint/src/uint.rs
+++ b/util/bigint/src/uint.rs
@ -36,10 +36,19 @@
 //! The functions here are designed to be fast.
 //!

-use standard::*;
-use from_json::*;
-use rustc_serialize::hex::ToHex;
+use std::fmt;
+use std::cmp;
+
+use std::mem;
+use std::str::{FromStr};
+use std::convert::From;
+use std::hash::{Hash, Hasher};
+use std::ops::*;
+use std::cmp::*;
+
 use serde;
+use rustc_serialize::hex::{FromHex, FromHexError, ToHex};
+

 macro_rules! impl_map_from {
 	($thing:ident, $from:ty, $to:ty) => {
@ -51,7 +60,7 @@ macro_rules! impl_map_from {
 	}
 }

-#[cfg(not(all(x64asm, target_arch="x86_64")))]
+#[cfg(not(all(asm_available, target_arch="x86_64")))]
 macro_rules! uint_overflowing_add {
 	($name:ident, $n_words:expr, $self_expr: expr, $other: expr) => ({
 		uint_overflowing_add_reg!($name, $n_words, $self_expr, $other)
@ -88,8 +97,7 @@ macro_rules! uint_overflowing_add_reg {
 	})
 }

-
-#[cfg(all(x64asm, target_arch="x86_64"))]
+#[cfg(all(asm_available, target_arch="x86_64"))]
 macro_rules! uint_overflowing_add {
 	(U256, $n_words: expr, $self_expr: expr, $other: expr) => ({
 		let mut result: [u64; 4] = unsafe { mem::uninitialized() };
@ -165,7 +173,7 @@ macro_rules! uint_overflowing_add {
 	)
 }

-#[cfg(not(all(x64asm, target_arch="x86_64")))]
+#[cfg(not(all(asm_available, target_arch="x86_64")))]
 macro_rules! uint_overflowing_sub {
 	($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
 		let res = overflowing!((!$other).overflowing_add(From::from(1u64)));
@ -174,7 +182,7 @@ macro_rules! uint_overflowing_sub {
 	})
 }

-#[cfg(all(x64asm, target_arch="x86_64"))]
+#[cfg(all(asm_available, target_arch="x86_64"))]
 macro_rules! uint_overflowing_sub {
 	(U256, $n_words: expr, $self_expr: expr, $other: expr) => ({
 		let mut result: [u64; 4] = unsafe { mem::uninitialized() };
@ -250,7 +258,7 @@ macro_rules! uint_overflowing_sub {
 	})
 }

-#[cfg(all(x64asm, target_arch="x86_64"))]
+#[cfg(all(asm_available, target_arch="x86_64"))]
 macro_rules! uint_overflowing_mul {
 	(U256, $n_words: expr, $self_expr: expr, $other: expr) => ({
 		let mut result: [u64; 4] = unsafe { mem::uninitialized() };
@ -370,7 +378,7 @@ macro_rules! uint_overflowing_mul {
 	)
 }

-#[cfg(not(all(x64asm, target_arch="x86_64")))]
+#[cfg(not(all(asm_available, target_arch="x86_64")))]
 macro_rules! uint_overflowing_mul {
 	($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
 		uint_overflowing_mul_reg!($name, $n_words, $self_expr, $other)
@ -381,7 +389,6 @@ macro_rules! uint_overflowing_mul_reg {
 	($name:ident, $n_words: expr, $self_expr: expr, $other: expr) => ({
 		let mut res = $name::from(0u64);
 		let mut overflow = false;
-		// TODO: be more efficient about this
 		for i in 0..(2 * $n_words) {
 			let v = overflowing!($self_expr.overflowing_mul_u32(($other >> (32 * i)).low_u32()), overflow);
 			let res2 = overflowing!(v.overflowing_shl(32 * i as u32), overflow);
@ -416,7 +423,7 @@ macro_rules! panic_on_overflow {
 }

 /// Large, fixed-length unsigned integer type.
-pub trait Uint: Sized + Default + FromStr + From<u64> + FromJson + fmt::Debug + fmt::Display + PartialOrd + Ord + PartialEq + Eq + Hash {
+pub trait Uint: Sized + Default + FromStr + From<u64> + fmt::Debug + fmt::Display + PartialOrd + Ord + PartialEq + Eq + Hash {

 	/// Returns new instance equalling zero.
 	fn zero() -> Self;
@ -779,22 +786,6 @@ macro_rules! construct_uint {
 			}
 		}

-		impl FromJson for $name {
-			fn from_json(json: &Json) -> Self {
-				match *json {
-					Json::String(ref s) => {
-						if s.len() >= 2 && &s[0..2] == "0x" {
-							FromStr::from_str(&s[2..]).unwrap_or_else(|_| Default::default())
-						} else {
-							Uint::from_dec_str(s).unwrap_or_else(|_| Default::default())
-						}
-					},
-					Json::U64(u) => From::from(u),
-					Json::I64(i) => From::from(i as u64),
-					_ => Uint::zero(),
-				}
-			}
-		}

 		impl_map_from!($name, u8, u64);
 		impl_map_from!($name, u16, u64);
@ -1100,7 +1091,7 @@ construct_uint!(U128, 2);
 impl U256 {
 	/// Multiplies two 256-bit integers to produce full 512-bit integer
 	/// No overflow possible
-	#[cfg(all(x64asm, target_arch="x86_64"))]
+	#[cfg(all(asm_available, target_arch="x86_64"))]
 	pub fn full_mul(self, other: U256) -> U512 {
 		let self_t: &[u64; 4] = unsafe { &mem::transmute(self) };
 		let other_t: &[u64; 4] = unsafe { &mem::transmute(other) };
@ -1239,7 +1230,7 @@ impl U256 {

 	/// Multiplies two 256-bit integers to produce full 512-bit integer
 	/// No overflow possible
-	#[cfg(not(all(x64asm, target_arch="x86_64")))]
+	#[cfg(not(all(asm_available, target_arch="x86_64")))]
 	pub fn full_mul(self, other: U256) -> U512 {
 		let self_512 = U512::from(self);
 		let other_512 = U512::from(other);
@ -1275,6 +1266,33 @@ impl From<U512> for U256 {
 	}
 }

+impl<'a> From<&'a U256> for U512 {
+	fn from(value: &'a U256) -> U512 {
+		let U256(ref arr) = *value;
+		let mut ret = [0; 8];
+		ret[0] = arr[0];
+		ret[1] = arr[1];
+		ret[2] = arr[2];
+		ret[3] = arr[3];
+		U512(ret)
+	}
+}
+
+impl<'a> From<&'a U512> for U256 {
+	fn from(value: &'a U512) -> U256 {
+		let U512(ref arr) = *value;
+		if arr[4] | arr[5] | arr[6] | arr[7] != 0 {
+			panic!("Overflow");
+		}
+		let mut ret = [0; 4];
+		ret[0] = arr[0];
+		ret[1] = arr[1];
+		ret[2] = arr[2];
+		ret[3] = arr[3];
+		U256(ret)
+	}
+}
+
 impl From<U256> for U128 {
 	fn from(value: U256) -> U128 {
 		let U256(ref arr) = value;
@ -1338,6 +1356,9 @@ pub const ZERO_U256: U256 = U256([0x00u64; 4]);
 /// Constant value of `U256::one()` that can be used for a reference saving an additional instance creation.
 pub const ONE_U256: U256 = U256([0x01u64, 0x00u64, 0x00u64, 0x00u64]);

+
+known_heap_size!(0, U128, U256);
+
 #[cfg(test)]
 mod tests {
 	use uint::{Uint, U128, U256, U512};
@ -1982,6 +2003,7 @@ mod tests {


 	#[test]
+	#[cfg_attr(feature = "dev", allow(cyclomatic_complexity))]
 	fn u256_multi_full_mul() {
 		let result = U256([0, 0, 0, 0]).full_mul(U256([0, 0, 0, 0]));
 		assert_eq!(U512([0, 0, 0, 0, 0, 0, 0, 0]), result);
--- a/util/build.rs
+++ b/util/build.rs
@ -1,13 +1,7 @@
 extern crate vergen;
-extern crate rustc_version;

 use vergen::*;
-use rustc_version::{version_meta, Channel};

 fn main() {
 	vergen(OutputFns::all()).unwrap();
-
-	if let Channel::Nightly = version_meta().channel {
-		println!("cargo:rustc-cfg=x64asm");
-	}
 }
--- a/util/src/common.rs
+++ b/util/src/common.rs
@ -19,10 +19,9 @@
 pub use standard::*;
 pub use from_json::*;
 pub use error::*;
-pub use hash::*;
-pub use uint::*;
 pub use bytes::*;
 pub use vector::*;
+pub use numbers::*;
 pub use sha3::*;

 #[macro_export]
--- a/util/src/crypto.rs
+++ b/util/src/crypto.rs
@ -16,9 +16,8 @@

 //! Ethcore crypto.

-use hash::*;
+use numbers::*;
 use bytes::*;
-use uint::*;
 use secp256k1::{key, Secp256k1};
 use rand::os::OsRng;

@ -151,8 +150,7 @@ impl KeyPair {

 /// EC functions
 pub mod ec {
-	use hash::*;
-	use uint::*;
+	use numbers::*;
 	use standard::*;
 	use crypto::*;
 	use crypto::{self};
--- a/util/src/from_json.rs
+++ b/util/src/from_json.rs
@ -17,6 +17,7 @@
 //! Coversion from json.

 use standard::*;
+use bigint::uint::*;

 #[macro_export]
 macro_rules! xjson {
@ -30,3 +31,20 @@ pub trait FromJson {
 	/// Convert a JSON value to an instance of this type.
 	fn from_json(json: &Json) -> Self;
 }
+
+impl FromJson for U256 {
+	fn from_json(json: &Json) -> Self {
+		match *json {
+			Json::String(ref s) => {
+				if s.len() >= 2 && &s[0..2] == "0x" {
+					FromStr::from_str(&s[2..]).unwrap_or_else(|_| Default::default())
+				} else {
+					Uint::from_dec_str(s).unwrap_or_else(|_| Default::default())
+				}
+			},
+			Json::U64(u) => From::from(u),
+			Json::I64(i) => From::from(i as u64),
+			_ => Uint::zero(),
+		}
+	}
+}
--- a/util/src/hash.rs
+++ b/util/src/hash.rs
@ -23,7 +23,7 @@ use rand::Rng;
 use rand::os::OsRng;
 use bytes::{BytesConvertable,Populatable};
 use from_json::*;
-use uint::{Uint, U256};
+use bigint::uint::{Uint, U256};
 use rustc_serialize::hex::ToHex;
 use serde;

@ -304,6 +304,8 @@ macro_rules! impl_hash {
 			}
 		}

+		impl Copy for $from {}
+		#[cfg_attr(feature="dev", allow(expl_impl_clone_on_copy))]
 		impl Clone for $from {
 			fn clone(&self) -> $from {
 				unsafe {
@ -595,7 +597,7 @@ pub fn h256_from_hex(s: &str) -> H256 {

 /// Convert `n` to an `H256`, setting the rightmost 8 bytes.
 pub fn h256_from_u64(n: u64) -> H256 {
-	use uint::U256;
+	use bigint::uint::U256;
 	H256::from(&U256::from(n))
 }

@ -631,7 +633,7 @@ pub static ZERO_H256: H256 = H256([0x00; 32]);
 #[cfg(test)]
 mod tests {
 	use hash::*;
-	use uint::*;
+	use bigint::uint::*;
 	use std::str::FromStr;

 	#[test]
--- a/util/src/heapsizeof.rs
+++ b/util/src/heapsizeof.rs
@ -16,8 +16,7 @@

 //! Calculates heapsize of util types.

-use uint::*;
 use hash::*;

 known_heap_size!(0, H32, H64, H128, Address, H256, H264, H512, H520, H1024, H2048);
-known_heap_size!(0, U128, U256);
+
--- a/util/src/journaldb.rs
+++ b/util/src/journaldb.rs
@ -121,6 +121,7 @@ impl JournalDB {
 		// and the key is safe to delete.

 		// record new commit's details.
+		debug!("commit: #{} ({}), end era: {:?}", now, id, end);
 		let batch = DBTransaction::new();
 		let mut counters = self.counters.write().unwrap();
 		{
@ -167,15 +168,18 @@ impl JournalDB {
 				&last
 			})) {
 				let rlp = Rlp::new(&rlp_data);
-				let inserts: Vec<H256> = rlp.val_at(1);
+				let mut inserts: Vec<H256> = rlp.val_at(1);
 				JournalDB::decrease_counters(&inserts, &mut counters);
 				// Collect keys to be removed. These are removed keys for canonical block, inserted for non-canonical
 				if canon_id == rlp.val_at(0) {
-					to_remove.extend(rlp.at(2).iter().map(|r| r.as_val::<H256>()));
+					let mut canon_deletes: Vec<H256> = rlp.val_at(2);
+					trace!("Purging nodes deleted from canon: {:?}", canon_deletes);
+					to_remove.append(&mut canon_deletes);
 					canon_inserts = inserts;
 				}
 				else {
-					to_remove.extend(inserts);
+					trace!("Purging nodes inserted in non-canon: {:?}", inserts);
+					to_remove.append(&mut inserts);
 				}
 				try!(batch.delete(&last));
 				index += 1;
@ -188,7 +192,7 @@ impl JournalDB {
 				try!(batch.delete(&h));
 				deletes += 1;
 			}
-			trace!("JournalDB: delete journal for time #{}.{}, (canon was {}): {} entries", end_era, index, canon_id, deletes);
+			debug!("commit: Delete journal for time #{}.{}, (canon was {}): {} entries", end_era, index, canon_id, deletes);
 		}

 		// Commit overlay insertions
@ -209,7 +213,7 @@ impl JournalDB {
 		}

 		try!(self.backing.write(batch));
-		trace!("JournalDB::commit() deleted {} nodes", deletes);
+		debug!("commit: Deleted {} nodes", deletes);
 		Ok(ret)
 	}

@ -258,7 +262,7 @@ impl JournalDB {
 				era -= 1;
 			}
 		}
-		trace!("Recovered {} counters", res.len());
+		debug!("Recovered {} counters", res.len());
 		res
 	}
 }
--- a/util/src/keys/geth_import.rs
+++ b/util/src/keys/geth_import.rs
@ -99,10 +99,20 @@ mod tests {
 	use common::*;
 	use keys::store::SecretStore;

+	fn test_path() -> &'static str {
+		match ::std::fs::metadata("res") {
+			Ok(_) => "res/geth_keystore",
+			Err(_) => "util/res/geth_keystore"
+		}
+	}
+
+	fn test_path_param(param_val: &'static str) -> String {
+		test_path().to_owned() + param_val
+	}

 	#[test]
 	fn can_enumerate() {
-		let keys = enumerate_geth_keys(Path::new("res/geth_keystore")).unwrap();
+		let keys = enumerate_geth_keys(Path::new(test_path())).unwrap();
 		assert_eq!(2, keys.len());
 	}

@ -110,7 +120,7 @@ mod tests {
 	fn can_import() {
 		let temp = ::devtools::RandomTempPath::create_dir();
 		let mut secret_store = SecretStore::new_in(temp.as_path());
-		import_geth_key(&mut secret_store, Path::new("res/geth_keystore/UTC--2016-02-17T09-20-45.721400158Z--3f49624084b67849c7b4e805c5988c21a430f9d9")).unwrap();
+		import_geth_key(&mut secret_store, Path::new(&test_path_param("/UTC--2016-02-17T09-20-45.721400158Z--3f49624084b67849c7b4e805c5988c21a430f9d9"))).unwrap();
 		let key = secret_store.account(&Address::from_str("3f49624084b67849c7b4e805c5988c21a430f9d9").unwrap());
 		assert!(key.is_some());
 	}
@ -119,7 +129,7 @@ mod tests {
 	fn can_import_directory() {
 		let temp = ::devtools::RandomTempPath::create_dir();
 		let mut secret_store = SecretStore::new_in(temp.as_path());
-		import_geth_keys(&mut secret_store, Path::new("res/geth_keystore")).unwrap();
+		import_geth_keys(&mut secret_store, Path::new(test_path())).unwrap();

 		let key = secret_store.account(&Address::from_str("3f49624084b67849c7b4e805c5988c21a430f9d9").unwrap());
 		assert!(key.is_some());
@ -134,7 +144,7 @@ mod tests {
 		let temp = ::devtools::RandomTempPath::create_dir();
 		{
 			let mut secret_store = SecretStore::new_in(temp.as_path());
-			import_geth_keys(&mut secret_store, Path::new("res/geth_keystore")).unwrap();
+			import_geth_keys(&mut secret_store, Path::new(test_path())).unwrap();
 		}

 		let key_directory = KeyDirectory::new(&temp.as_path());
@ -156,7 +166,7 @@ mod tests {

 		let temp = ::devtools::RandomTempPath::create_dir();
 		let mut secret_store = SecretStore::new_in(temp.as_path());
-		import_geth_keys(&mut secret_store, Path::new("res/geth_keystore")).unwrap();
+		import_geth_keys(&mut secret_store, Path::new(test_path())).unwrap();

 		let val = secret_store.get::<Bytes>(&H128::from_str("62a0ad73556d496a8e1c0783d30d3ace").unwrap(), "123");
 		assert!(val.is_ok());
--- a/util/src/lib.rs
+++ b/util/src/lib.rs
@ -16,7 +16,6 @@

 #![warn(missing_docs)]
 #![cfg_attr(feature="dev", feature(plugin))]
-#![cfg_attr(x64asm, feature(asm))]
 #![cfg_attr(feature="dev", plugin(clippy))]

 // Clippy settings
@ -111,15 +110,16 @@ extern crate libc;
 extern crate rustc_version;
 extern crate target_info;
 extern crate vergen;
+extern crate bigint;

 pub mod standard;
 #[macro_use]
 pub mod from_json;
 #[macro_use]
 pub mod common;
+pub mod numbers;
 pub mod error;
 pub mod hash;
-pub mod uint;
 pub mod bytes;
 pub mod rlp;
 pub mod misc;
--- a/util/src/misc.rs
+++ b/util/src/misc.rs
@ -18,6 +18,7 @@

 use std::fs::File;
 use common::*;
+use rlp::{Stream, RlpStream};
 use target_info::Target;
 use rustc_version;

@ -69,5 +70,19 @@ pub fn contents(name: &str) -> Result<Bytes, UtilError> {

 /// Get the standard version string for this software.
 pub fn version() -> String {
-	format!("Parity//{}-{}-{}/{}-{}-{}/rustc{}", env!("CARGO_PKG_VERSION"), short_sha(), commit_date().replace("-", ""), Target::arch(), Target::os(), Target::env(), rustc_version::version())
+	format!("Parity/v{}-{}-{}/{}-{}-{}/rustc{}", env!("CARGO_PKG_VERSION"), short_sha(), commit_date().replace("-", ""), Target::arch(), Target::os(), Target::env(), rustc_version::version())
+}
+
+/// Get the standard version data for this software.
+pub fn version_data() -> Bytes {
+	let mut s = RlpStream::new_list(4);
+	let v =
+		(u32::from_str(env!("CARGO_PKG_VERSION_MAJOR")).unwrap() << 16) +
+		(u32::from_str(env!("CARGO_PKG_VERSION_MINOR")).unwrap() << 8) +
+		u32::from_str(env!("CARGO_PKG_VERSION_PATCH")).unwrap();
+	s.append(&v);
+	s.append(&"Parity");
+	s.append(&format!("{}", rustc_version::version()));
+	s.append(&&Target::os()[0..2]);
+	s.out()
 }
--- a/util/src/numbers.rs
+++ b/util/src/numbers.rs
@ -0,0 +1,20 @@
+// 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/>.
+
+//! Utils number types.
+
+pub use hash::*;
+pub use bigint::uint::*;
--- a/util/src/rlp/bytes.rs
+++ b/util/src/rlp/bytes.rs
@ -21,7 +21,7 @@ use std::mem;
 use std::fmt;
 use std::cmp::Ordering;
 use std::error::Error as StdError;
-use uint::{Uint, U128, U256};
+use bigint::uint::{Uint, U128, U256};
 use hash::FixedHash;
 use elastic_array::*;

--- a/util/src/rlp/tests.rs
+++ b/util/src/rlp/tests.rs
@ -21,7 +21,7 @@ use std::{fmt, cmp};
 use std::str::FromStr;
 use rlp;
 use rlp::{UntrustedRlp, RlpStream, View, Stream, DecoderError};
-use uint::U256;
+use bigint::uint::U256;

 #[test]
 fn rlp_at() {
--- a/util/src/table.rs
+++ b/util/src/table.rs
@ -111,7 +111,7 @@ impl<Row, Col, Val> Table<Row, Col, Val>
 	///
 	/// Returns previous value (if any)
 	pub fn insert(&mut self, row: Row, col: Col, val: Val) -> Option<Val> {
-		self.map.entry(row).or_insert_with(|| HashMap::new()).insert(col, val)
+		self.map.entry(row).or_insert_with(HashMap::new).insert(col, val)
 	}
 }