Extrinsic pool (#182)

* Use latest version of txpool.

* Initial version of the pool.

* Fix abstraction.

* Implement watchers and notifications.

* Return hash from RPC.

* Remove commented code.

* Remove client dep.

* Fix tests.

substrate/Cargo.lock

@@ -229,6 +229,7 @@ dependencies = [
  "substrate-client 0.1.0",
  "substrate-codec 0.1.0",
  "substrate-executor 0.1.0",
+ "substrate-extrinsic-pool 0.1.0",
  "substrate-primitives 0.1.0",
  "substrate-rpc 0.1.0",
  "substrate-rpc-servers 0.1.0",
@@ -1429,16 +1430,15 @@ version = "0.1.0"
 dependencies = [
  "ed25519 0.1.0",
  "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "polkadot-api 0.1.0",
  "polkadot-primitives 0.1.0",
  "polkadot-runtime 0.1.0",
  "substrate-client 0.1.0",
  "substrate-codec 0.1.0",
+ "substrate-extrinsic-pool 0.1.0",
  "substrate-primitives 0.1.0",
- "substrate-rpc 0.1.0",
  "substrate-runtime-primitives 0.1.0",
- "transaction-pool 1.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1942,6 +1942,18 @@ dependencies = [
  "wasmi 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "substrate-extrinsic-pool"
+version = "0.1.0"
+dependencies = [
+ "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "substrate-primitives 0.1.0",
+ "transaction-pool 1.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "substrate-keyring"
 version = "0.1.0"
@@ -2025,6 +2037,7 @@ dependencies = [
  "parking_lot 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-client 0.1.0",
  "substrate-executor 0.1.0",
+ "substrate-extrinsic-pool 0.1.0",
  "substrate-primitives 0.1.0",
  "substrate-state-machine 0.1.0",
  "substrate-test-client 0.1.0",

substrate/Cargo.toml

@@ -22,22 +22,22 @@ members = [
 	"polkadot/parachain",
 	"polkadot/primitives",
 	"polkadot/runtime",
+	"polkadot/service",
 	"polkadot/statement-table",
 	"polkadot/transaction-pool",
-	"polkadot/service",
-
 	"substrate/bft",
 	"substrate/client",
 	"substrate/client/db",
 	"substrate/codec",
 	"substrate/environmental",
 	"substrate/executor",
+	"substrate/extrinsic-pool",
 	"substrate/keyring",
-	"substrate/network",
 	"substrate/misbehavior-check",
+	"substrate/network",
 	"substrate/primitives",
-	"substrate/rpc-servers",
 	"substrate/rpc",
+	"substrate/rpc-servers",
 	"substrate/runtime-io",
 	"substrate/runtime-sandbox",
 	"substrate/runtime-std",
@@ -55,10 +55,10 @@ members = [
 	"substrate/state-machine",
 	"substrate/test-runtime",
 
-	"demo/runtime",
-	"demo/primitives",
-	"demo/executor",
 	"demo/cli",
+	"demo/executor",
+	"demo/primitives",
+	"demo/runtime",
 	"safe-mix",
 	"subkey",
 ]

substrate/demo/cli/Cargo.toml

@@ -17,6 +17,7 @@ tokio-core = "0.1.12"
 triehash = "0.1"
 substrate-client = { path = "../../substrate/client" }
 substrate-codec = { path = "../../substrate/codec" }
+substrate-extrinsic-pool = { path = "../../substrate/extrinsic-pool" }
 substrate-runtime-io = { path = "../../substrate/runtime-io" }
 substrate-state-machine = { path = "../../substrate/state-machine" }
 substrate-executor = { path = "../../substrate/executor" }

substrate/demo/cli/src/lib.rs

@@ -31,6 +31,7 @@ extern crate substrate_rpc;
 extern crate substrate_rpc_servers as rpc;
 extern crate substrate_runtime_io as runtime_io;
 extern crate substrate_state_machine as state_machine;
+extern crate substrate_extrinsic_pool as extrinsic_pool;
 extern crate demo_executor;
 extern crate demo_primitives;
 extern crate demo_runtime;
@@ -53,11 +54,14 @@ use demo_runtime::{GenesisConfig, ConsensusConfig, CouncilConfig, DemocracyConfi
 	SessionConfig, StakingConfig, BuildExternalities};
 use futures::{Future, Sink, Stream};
 
-
 struct DummyPool;
-impl substrate_rpc::author::AuthorApi for DummyPool {
+impl extrinsic_pool::api::ExtrinsicPool for DummyPool {
-	fn submit_extrinsic(&self, _: primitives::block::Extrinsic) -> substrate_rpc::author::error::Result<()> {
+	type Error = extrinsic_pool::txpool::Error;
-		Err(substrate_rpc::author::error::ErrorKind::Unimplemented.into())
+
+	fn submit(&self, _: Vec<primitives::block::Extrinsic>)
+		-> Result<Vec<primitives::block::ExtrinsicHash>, Self::Error>
+	{
+		Err("unimplemented".into())
 	}
 }
 
@@ -156,7 +160,7 @@ pub fn run<I, T>(args: I) -> error::Result<()> where
 	let _rpc_servers = {
 		let handler = || {
 			let chain = rpc::apis::chain::Chain::new(client.clone(), core.remote());
-			rpc::rpc_handler(client.clone(), chain, DummyPool, DummySystem)
+			rpc::rpc_handler(client.clone(), chain, Arc::new(DummyPool), DummySystem)
 		};
 		let http_address = "127.0.0.1:9933".parse().unwrap();
 		let ws_address = "127.0.0.1:9944".parse().unwrap();

substrate/polkadot/cli/src/lib.rs

@@ -61,39 +61,11 @@ mod informant;
 use std::io;
 use std::net::SocketAddr;
 use std::path::{Path, PathBuf};
-use std::sync::Arc;
 
 use futures::sync::mpsc;
 use futures::{Sink, Future, Stream};
 use tokio_core::reactor;
-use parking_lot::Mutex;
 use service::ChainSpec;
-use primitives::block::Extrinsic;
-
-struct RpcTransactionPool {
-	inner: Arc<Mutex<txpool::TransactionPool>>,
-	network: Arc<network::Service>,
-}
-
-impl substrate_rpc::author::AuthorApi for RpcTransactionPool {
-	fn submit_extrinsic(&self, xt: Extrinsic) -> substrate_rpc::author::error::Result<()> {
-		use primitives::hexdisplay::HexDisplay;
-		use polkadot_runtime::UncheckedExtrinsic;
-		use codec::Slicable;
-
-		info!("Extrinsic submitted: {}", HexDisplay::from(&xt.0));
-		let decoded = xt.using_encoded(|ref mut s| UncheckedExtrinsic::decode(s))
-			.ok_or(substrate_rpc::author::error::ErrorKind::InvalidFormat)?;
-
-		info!("Correctly formatted: {:?}", decoded);
-
-		self.inner.lock().import(decoded)
-			.map_err(|_| substrate_rpc::author::error::ErrorKind::PoolError)?;
-
-		self.network.trigger_repropagate();
-		Ok(())
-	}
-}
 
 struct Configuration(service::Configuration);
 
@@ -238,11 +210,12 @@ fn run_until_exit<B, E>(mut core: reactor::Core, service: service::Service<B, E>
 
 		let handler = || {
 			let chain = rpc::apis::chain::Chain::new(service.client(), core.remote());
-			let pool = RpcTransactionPool {
+			rpc::rpc_handler(
-				inner: service.transaction_pool(),
+				service.client(),
-				network: service.network(),
+				chain,
-			};
+				service.transaction_pool(),
-			rpc::rpc_handler(service.client(), chain, pool, Configuration(config.clone()))
+				Configuration(config.clone()),
+			)
 		};
 		(
 			start_server(http_address, |address| rpc::start_http(address, handler())),

substrate/polkadot/consensus/src/lib.rs

@@ -78,7 +78,6 @@ use tokio_core::reactor::{Handle, Timeout, Interval};
 
 use futures::prelude::*;
 use futures::future::{self, Shared};
-use parking_lot::Mutex;
 use collation::CollationFetch;
 use dynamic_inclusion::DynamicInclusion;
 
@@ -226,7 +225,7 @@ pub struct ProposerFactory<C, N, P> {
 	/// The client instance.
 	pub client: Arc<C>,
 	/// The transaction pool.
-	pub transaction_pool: Arc<Mutex<TransactionPool>>,
+	pub transaction_pool: Arc<TransactionPool>,
 	/// The backing network handle.
 	pub network: N,
 	/// Parachain collators.
@@ -319,7 +318,7 @@ pub struct Proposer<C: PolkadotApi, R, P> {
 	random_seed: Hash,
 	router: R,
 	table: Arc<SharedTable>,
-	transaction_pool: Arc<Mutex<TransactionPool>>,
+	transaction_pool: Arc<TransactionPool>,
 }
 
 impl<C, R, P> bft::Proposer for Proposer<C, R, P>
@@ -495,17 +494,16 @@ impl<C, R, P> bft::Proposer for Proposer<C, R, P>
 		use primitives::bft::{MisbehaviorKind, MisbehaviorReport};
 		use polkadot_runtime::{Call, Extrinsic, UncheckedExtrinsic, ConsensusCall};
 
+
 		let local_id = self.local_key.public().0;
-		let mut pool = self.transaction_pool.lock();
 		let mut next_index = {
 			let readiness_evaluator = Ready::create(self.parent_id.clone(), &*self.client);
-
+			let cur_index = self.transaction_pool.cull_and_get_pending(readiness_evaluator, |pending| pending
-			pool.cull(None, readiness_evaluator.clone());
-			let cur_index = pool.pending(readiness_evaluator)
 				.filter(|tx| tx.as_ref().as_ref().signed == local_id)
 				.last()
 				.map(|tx| Ok(tx.as_ref().as_ref().index))
-				.unwrap_or_else(|| self.client.index(&self.parent_id, local_id));
+				.unwrap_or_else(|| self.client.index(&self.parent_id, local_id))
+			);
 
 			match cur_index {
 				Ok(cur_index) => cur_index + 1,
@@ -541,7 +539,7 @@ impl<C, R, P> bft::Proposer for Proposer<C, R, P>
 			let signature = self.local_key.sign(&extrinsic.encode()).into();
 			let uxt = UncheckedExtrinsic { extrinsic, signature };
 
-			pool.import(uxt).expect("locally signed extrinsic is valid; qed");
+			self.transaction_pool.import_unchecked_extrinsic(uxt).expect("locally signed extrinsic is valid; qed");
 		}
 	}
 }
@@ -609,7 +607,7 @@ pub struct CreateProposal<C: PolkadotApi, R, P: Collators>  {
 	parent_number: BlockNumber,
 	parent_id: C::CheckedBlockId,
 	client: Arc<C>,
-	transaction_pool: Arc<Mutex<TransactionPool>>,
+	transaction_pool: Arc<TransactionPool>,
 	collation: CollationFetch<P, C>,
 	router: R,
 	table: Arc<SharedTable>,
@@ -631,37 +629,33 @@ impl<C, R, P> CreateProposal<C, R, P>
 			candidates,
 		)?;
 
-		let readiness_evaluator = Ready::create(self.parent_id.clone(), &*self.client);
-
 		{
-			let mut pool = self.transaction_pool.lock();
+			let readiness_evaluator = Ready::create(self.parent_id.clone(), &*self.client);
 			let mut unqueue_invalid = Vec::new();
-			let mut pending_size = 0;
+			self.transaction_pool.cull_and_get_pending(readiness_evaluator, |pending_iterator| {
-
+				let mut pending_size = 0;
-			pool.cull(None, readiness_evaluator.clone());
+				for pending in pending_iterator {
-			for pending in pool.pending(readiness_evaluator.clone()) {
+					// skip and cull transactions which are too large.
-				// skip and cull transactions which are too large.
+					if pending.encoded_size() > MAX_TRANSACTIONS_SIZE {
-				if pending.encoded_size() > MAX_TRANSACTIONS_SIZE {
-					unqueue_invalid.push(pending.hash().clone());
-					continue
-				}
-
-				if pending_size + pending.encoded_size() >= MAX_TRANSACTIONS_SIZE { break }
-
-				match block_builder.push_extrinsic(pending.as_transaction().clone()) {
-					Ok(()) => {
-						pending_size += pending.encoded_size();
-					}
-					Err(e) => {
-						trace!(target: "transaction-pool", "Invalid transaction: {}", e);
 						unqueue_invalid.push(pending.hash().clone());
+						continue
+					}
+
+					if pending_size + pending.encoded_size() >= MAX_TRANSACTIONS_SIZE { break }
+
+					match block_builder.push_extrinsic(pending.as_transaction().clone()) {
+						Ok(()) => {
+							pending_size += pending.encoded_size();
+						}
+						Err(e) => {
+							trace!(target: "transaction-pool", "Invalid transaction: {}", e);
+							unqueue_invalid.push(pending.hash().clone());
+						}
 					}
 				}
-			}
+			});
 
-			for tx_hash in unqueue_invalid {
+			self.transaction_pool.remove(&unqueue_invalid, false);
-				pool.remove(&tx_hash, false);
-			}
 		}
 
 		let polkadot_block = block_builder.bake();

substrate/polkadot/consensus/src/service.rs

@@ -28,7 +28,6 @@ use client::{BlockchainEvents, ChainHead};
 use ed25519;
 use futures::prelude::*;
 use futures::{future, Canceled};
-use parking_lot::Mutex;
 use polkadot_api::LocalPolkadotApi;
 use polkadot_primitives::AccountId;
 use polkadot_primitives::parachain::{Id as ParaId, BlockData, Extrinsic, CandidateReceipt};
@@ -237,7 +236,7 @@ impl Service {
 		client: Arc<C>,
 		api: Arc<A>,
 		network: Arc<net::ConsensusService>,
-		transaction_pool: Arc<Mutex<TransactionPool>>,
+		transaction_pool: Arc<TransactionPool>,
 		parachain_empty_duration: Duration,
 		key: ed25519::Pair,
 	) -> Service

substrate/polkadot/service/src/config.rs

@@ -22,7 +22,7 @@ pub use network::NetworkConfiguration;
 
 /// The chain specification (this should eventually be replaced by a more general JSON-based chain
 /// specification).
-#[derive(Clone)]
+#[derive(Clone, Copy)]
 pub enum ChainSpec {
 	/// Whatever the current runtime is, with just Alice as an auth.
 	Development,
@@ -33,6 +33,7 @@ pub enum ChainSpec {
 }
 
 /// Service configuration.
+#[derive(Clone)]
 pub struct Configuration {
 	/// Node roles.
 	pub roles: Role,
@@ -63,21 +64,3 @@ impl Default for Configuration {
 		}
 	}
 }
-
-impl Clone for Configuration {
-	fn clone(&self) -> Configuration {
-		Configuration {
-			roles: self.roles.clone(),
-			transaction_pool: transaction_pool::Options {
-				max_count: self.transaction_pool.max_count.clone(),
-				max_mem_usage: self.transaction_pool.max_mem_usage.clone(),
-				max_per_sender: self.transaction_pool.max_per_sender.clone(),
-			},
-			network: self.network.clone(),
-			keystore_path: self.keystore_path.clone(),
-			database_path: self.database_path.clone(),
-			keys: self.keys.clone(),
-			chain_spec: self.chain_spec.clone(),
-		}
-	}
-}

substrate/polkadot/service/src/lib.rs

@@ -50,14 +50,14 @@ extern crate hex_literal;
 mod error;
 mod config;
 
+use std::collections::HashMap;
 use std::sync::Arc;
 use std::thread;
 use futures::prelude::*;
-use parking_lot::Mutex;
 use tokio_core::reactor::Core;
 use codec::Slicable;
-use primitives::block::{Id as BlockId, Extrinsic, ExtrinsicHash, HeaderHash, Header};
+use primitives::block::{Id as BlockId, ExtrinsicHash, HeaderHash, Header};
-use primitives::{AuthorityId, hashing};
+use primitives::{AuthorityId};
 use transaction_pool::TransactionPool;
 use substrate_executor::NativeExecutor;
 use polkadot_executor::Executor as LocalDispatch;
@@ -80,13 +80,13 @@ pub struct Service<B, E> {
 	thread: Option<thread::JoinHandle<()>>,
 	client: Arc<Client<B, E>>,
 	network: Arc<network::Service>,
-	transaction_pool: Arc<Mutex<TransactionPool>>,
+	transaction_pool: Arc<TransactionPool>,
 	signal: Option<Signal>,
 	_consensus: Option<consensus::Service>,
 }
 
 struct TransactionPoolAdapter<B, E, A> where A: Send + Sync, E: Send + Sync {
-	pool: Arc<Mutex<TransactionPool>>,
+	pool: Arc<TransactionPool>,
 	client: Arc<Client<B, E>>,
 	api: Arc<A>,
 }
@@ -108,19 +108,22 @@ impl<B, E, A> network::TransactionPool for TransactionPoolAdapter<B, E, A>
 		};
 
 		let id = self.api.check_id(BlockId::Hash(best_block)).expect("Best block is always valid; qed.");
-		let mut pool = self.pool.lock();
+		let ready = transaction_pool::Ready::create(id, &*self.api);
-		pool.cull(None, transaction_pool::Ready::create(id.clone(), &*self.api));
+
-		pool.pending(transaction_pool::Ready::create(id, &*self.api)).map(|t| {
+		self.pool.cull_and_get_pending(ready, |pending| pending
-			let hash = ::primitives::Hash::from(&t.hash()[..]);
+			.map(|t| {
-			let tx = codec::Slicable::encode(t.as_transaction());
+				let hash = ::primitives::Hash::from(&t.hash()[..]);
-			(hash, tx)
+				let tx = codec::Slicable::encode(t.as_transaction());
-		}).collect()
+				(hash, tx)
+			})
+			.collect()
+		)
 	}
 
 	fn import(&self, transaction: &[u8]) -> Option<ExtrinsicHash> {
-		if let Some(tx) = codec::Slicable::decode(&mut &transaction[..]) {
+		if let Some(uxt) = codec::Slicable::decode(&mut &transaction[..]) {
-			match self.pool.lock().import(tx) {
+			match self.pool.import_unchecked_extrinsic(uxt) {
-				Ok(t) => Some(t.hash()[..].into()),
+				Ok(xt) => Some(*xt.hash()),
 				Err(e) => match *e.kind() {
 					transaction_pool::ErrorKind::AlreadyImported(hash) => Some(hash[..].into()),
 					_ => {
@@ -134,6 +137,10 @@ impl<B, E, A> network::TransactionPool for TransactionPoolAdapter<B, E, A>
 			None
 		}
 	}
+
+	fn on_broadcasted(&self, propagations: HashMap<ExtrinsicHash, Vec<String>>) {
+		self.pool.on_broadcasted(propagations)
+	}
 }
 
 pub struct ChainConfig {
@@ -341,7 +348,7 @@ impl<B, E> Service<B, E>
 			C: Fn(
 					Arc<Client<B, E>>,
 					Arc<network::Service>,
-					Arc<Mutex<TransactionPool>>,
+					Arc<TransactionPool>,
 					&Keystore
 				) -> Result<Option<consensus::Service>, error::Error>,
 			A: PolkadotApi + Send + Sync + 'static,
@@ -383,7 +390,7 @@ impl<B, E> Service<B, E>
 		let api = api_creator(client.clone());
 		let best_header = client.best_block_header()?;
 		info!("Starting Polkadot. Best block is #{}", best_header.number);
-		let transaction_pool = Arc::new(Mutex::new(TransactionPool::new(config.transaction_pool)));
+		let transaction_pool = Arc::new(TransactionPool::new(config.transaction_pool));
 		let transaction_pool_adapter = Arc::new(TransactionPoolAdapter {
 			pool: transaction_pool.clone(),
 			client: client.clone(),
@@ -414,14 +421,28 @@ impl<B, E> Service<B, E>
 
 				thread_barrier.wait();
 				let mut core = Core::new().expect("tokio::Core could not be created");
-				let events = client.import_notification_stream().for_each(move |notification| {
-					network.on_block_imported(notification.hash, &notification.header);
-					prune_imported(&*client, &*txpool, notification.hash);
 
-					Ok(())
+				// block notifications
-				});
+				let network1 = network.clone();
+				let txpool1 = txpool.clone();
+				let events = client.import_notification_stream()
+					.for_each(move |notification| {
+						network1.on_block_imported(notification.hash, &notification.header);
+						prune_imported(&*api, &*txpool1, notification.hash);
 
+						Ok(())
+					});
 				core.handle().spawn(events);
+
+				// transaction notifications
+				let events = txpool.import_notification_stream()
+					// TODO [ToDr] Consider throttling?
+					.for_each(move |_| {
+						network.trigger_repropagate();
+						Ok(())
+					});
+				core.handle().spawn(events);
+
 				if let Err(e) = core.run(exit) {
 					debug!("Polkadot service event loop shutdown with {:?}", e);
 				}
@@ -457,30 +478,22 @@ impl<B, E> Service<B, E>
 	}
 
 	/// Get shared transaction pool instance.
-	pub fn transaction_pool(&self) -> Arc<Mutex<TransactionPool>> {
+	pub fn transaction_pool(&self) -> Arc<TransactionPool> {
 		self.transaction_pool.clone()
 	}
 }
 
-fn prune_transactions(pool: &mut TransactionPool, extrinsics: &[Extrinsic]) {
-	for extrinsic in extrinsics {
-		let hash: _ = hashing::blake2_256(&extrinsic.encode()).into();
-		pool.remove(&hash, true);
-	}
-}
-
 /// Produce a task which prunes any finalized transactions from the pool.
-pub fn prune_imported<B, E>(client: &Client<B, E>, pool: &Mutex<TransactionPool>, hash: HeaderHash)
+pub fn prune_imported<A>(api: &A, pool: &TransactionPool, hash: HeaderHash)
 	where
-		B: Backend + Send + Sync,
+		A: PolkadotApi,
-		E: CallExecutor + Send + Sync,
-		client::error::Error: From<<<B as Backend>::State as state_machine::backend::Backend>::Error>
 {
-	let id = BlockId::Hash(hash);
+	match api.check_id(BlockId::Hash(hash)) {
-	match client.body(&id) {
+		Ok(id) => {
-		Ok(Some(body)) => prune_transactions(&mut *pool.lock(), &body[..]),
+			let ready = transaction_pool::Ready::create(id, api);
-		Ok(None) => warn!("Missing imported block {:?}", hash),
+			pool.cull(None, ready);
-		Err(e) => warn!("Failed to fetch block: {:?}", e),
+		},
+		Err(e) => warn!("Failed to check block id: {:?}", e),
 	}
 }
 

substrate/polkadot/transaction-pool/Cargo.toml

@@ -4,15 +4,14 @@ version = "0.1.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 
 [dependencies]
-log = "0.4.0"
+log = "0.3.0"
-transaction-pool = "1.12.0"
 error-chain = "0.11"
 polkadot-api = { path = "../api" }
 polkadot-primitives = { path = "../primitives" }
 polkadot-runtime = { path = "../runtime" }
 substrate-client = { path = "../../substrate/client" }
-substrate-rpc = { path = "../../substrate/rpc" }
+substrate-codec = { path = "../../substrate/codec" }
+substrate-extrinsic-pool = { path = "../../substrate/extrinsic-pool" }
 substrate-primitives = { path = "../../substrate/primitives" }
 substrate-runtime-primitives = { path = "../../substrate/runtime/primitives" }
-substrate-codec = { path = "../../substrate/codec" }
 ed25519 = { path = "../../substrate/ed25519" }

substrate/polkadot/transaction-pool/src/error.rs

@@ -0,0 +1,61 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use extrinsic_pool::{self, txpool};
+use primitives::Hash;
+use runtime::UncheckedExtrinsic;
+
+error_chain! {
+	links {
+		Pool(txpool::Error, txpool::ErrorKind);
+	}
+	errors {
+		/// Unexpected extrinsic format submitted
+		InvalidExtrinsicFormat {
+			description("Invalid extrinsic format."),
+			display("Invalid extrinsic format."),
+		}
+		/// Attempted to queue an inherent transaction.
+		IsInherent(xt: UncheckedExtrinsic) {
+			description("Inherent transactions cannot be queued."),
+			display("Inehrent transactions cannot be queued."),
+		}
+		/// Attempted to queue a transaction with bad signature.
+		BadSignature(xt: UncheckedExtrinsic) {
+			description("Transaction had bad signature."),
+			display("Transaction had bad signature."),
+		}
+		/// Attempted to queue a transaction that is already in the pool.
+		AlreadyImported(hash: Hash) {
+			description("Transaction is already in the pool."),
+			display("Transaction {:?} is already in the pool.", hash),
+		}
+		/// Import error.
+		Import(err: Box<::std::error::Error + Send>) {
+			description("Error importing transaction"),
+			display("Error importing transaction: {}", err.description()),
+		}
+	}
+}
+
+impl extrinsic_pool::api::Error for Error {
+	fn into_pool_error(self) -> ::std::result::Result<txpool::Error, Self> {
+		match self {
+			Error(ErrorKind::Pool(e), c) => Ok(txpool::Error(e, c)),
+			e => Err(e),
+		}
+	}
+}

substrate/polkadot/transaction-pool/src/lib.rs

@@ -1,4 +1,4 @@
-// Copyright 2017 Parity Technologies (UK) Ltd.
+// Copyright 2018 Parity Technologies (UK) Ltd.
 // This file is part of Polkadot.
 
 // Polkadot is free software: you can redistribute it and/or modify
@@ -16,12 +16,12 @@
 
 extern crate ed25519;
 extern crate substrate_codec as codec;
+extern crate substrate_extrinsic_pool as extrinsic_pool;
 extern crate substrate_primitives as substrate_primitives;
-extern crate substrate_runtime_primitives as substrate_runtime_primitives;
+extern crate substrate_runtime_primitives;
 extern crate polkadot_runtime as runtime;
 extern crate polkadot_primitives as primitives;
 extern crate polkadot_api;
-extern crate transaction_pool;
 
 #[macro_use]
 extern crate error_chain;
@@ -29,19 +29,27 @@ extern crate error_chain;
 #[macro_use]
 extern crate log;
 
-use std::collections::HashMap;
+mod error;
-use std::cmp::Ordering;
-use std::sync::Arc;
 
+use std::{
+	cmp::Ordering,
+	collections::HashMap,
+	ops::Deref,
+	sync::Arc,
+};
+
+use codec::Slicable;
+use extrinsic_pool::{Pool, txpool::{self, Readiness, scoring::{Change, Choice}}};
 use polkadot_api::PolkadotApi;
-use primitives::{AccountId, Timestamp, Hash};
 use primitives::parachain::CandidateReceipt;
+use primitives::{AccountId, Timestamp, Hash};
 use runtime::{Block, UncheckedExtrinsic, TimestampCall, ParachainsCall, Call};
+use substrate_primitives::block::{Extrinsic, ExtrinsicHash};
+use substrate_primitives::hexdisplay::HexDisplay;
 use substrate_runtime_primitives::traits::{Bounded, Checkable};
-use transaction_pool::{Transaction, Pool, Readiness};
-use transaction_pool::scoring::{Change, Choice};
 
-pub use transaction_pool::{Options, Status, LightStatus, NoopListener, VerifiedTransaction as VerifiedTransactionOps};
+pub use extrinsic_pool::txpool::{Options, Status, LightStatus, VerifiedTransaction as VerifiedTransactionOps};
+pub use error::{Error, ErrorKind, Result};
 
 /// Useful functions for working with Polkadot blocks.
 pub struct PolkadotBlock {
@@ -127,48 +135,17 @@ impl From<PolkadotBlock> for Block {
 	}
 }
 
-/// Iterator over pending transactions.
-pub type PendingIterator<'a, C> =
-	transaction_pool::PendingIterator<'a, VerifiedTransaction, Ready<'a, C>, Scoring, NoopListener>;
-
-error_chain! {
-	errors {
-		/// Attempted to queue an inherent transaction.
-		IsInherent(xt: UncheckedExtrinsic) {
-			description("Inherent transactions cannot be queued."),
-			display("Inehrent transactions cannot be queued."),
-		}
-		/// Attempted to queue a transaction with bad signature.
-		BadSignature(xt: UncheckedExtrinsic) {
-			description("Transaction had bad signature."),
-			display("Transaction had bad signature."),
-		}
-		/// Attempted to queue a transaction that is already in the pool.
-		AlreadyImported(hash: Hash) {
-			description("Transaction is already in the pool."),
-			display("Transaction {:?} is already in the pool.", hash),
-		}
-		/// Import error.
-		Import(err: Box<::std::error::Error + Send>) {
-			description("Error importing transaction"),
-			display("Error importing transaction: {}", err.description()),
-		}
-	}
-}
-
 /// A verified transaction which should be includable and non-inherent.
 #[derive(Debug, Clone)]
 pub struct VerifiedTransaction {
 	inner: <UncheckedExtrinsic as Checkable>::Checked,
-	hash: Hash,
+	hash: ExtrinsicHash,
-	address: AccountId,
-	insertion_id: u64,
 	encoded_size: usize,
 }
 
 impl VerifiedTransaction {
 	/// Attempt to verify a transaction.
-	fn create(xt: UncheckedExtrinsic, insertion_id: u64) -> Result<Self> {
+	fn create(xt: UncheckedExtrinsic) -> Result<Self> {
 		if !xt.is_signed() {
 			bail!(ErrorKind::IsInherent(xt))
 		}
@@ -176,15 +153,11 @@ impl VerifiedTransaction {
 		let message = codec::Slicable::encode(&xt);
 		match xt.check() {
 			Ok(xt) => {
-				// TODO: make transaction-pool use generic types.
 				let hash = substrate_primitives::hashing::blake2_256(&message);
-				let address = xt.signed;
 				Ok(VerifiedTransaction {
 					inner: xt,
 					hash: hash.into(),
 					encoded_size: message.len(),
-					address,
-					insertion_id,
 				})
 			}
 			Err(xt) => Err(ErrorKind::BadSignature(xt).into()),
@@ -208,7 +181,7 @@ impl VerifiedTransaction {
 
 	/// Get the account ID of the sender of this transaction.
 	pub fn sender(&self) -> &AccountId {
-		&self.address
+		&self.inner.signed
 	}
 
 	/// Get encoded size of the transaction.
@@ -223,16 +196,16 @@ impl AsRef< <UncheckedExtrinsic as Checkable>::Checked > for VerifiedTransaction
 	}
 }
 
-impl transaction_pool::VerifiedTransaction for VerifiedTransaction {
+impl txpool::VerifiedTransaction for VerifiedTransaction {
 	type Hash = Hash;
 	type Sender = AccountId;
 
-	fn hash(&self) -> &Hash {
+	fn hash(&self) -> &Self::Hash {
 		&self.hash
 	}
 
-	fn sender(&self) -> &AccountId {
+	fn sender(&self) -> &Self::Sender {
-		&self.address
+		&self.inner.signed
 	}
 
 	fn mem_usage(&self) -> usize {
@@ -244,7 +217,7 @@ impl transaction_pool::VerifiedTransaction for VerifiedTransaction {
 #[derive(Debug)]
 pub struct Scoring;
 
-impl transaction_pool::Scoring<VerifiedTransaction> for Scoring {
+impl txpool::Scoring<VerifiedTransaction> for Scoring {
 	type Score = u64;
 	type Event = ();
 
@@ -258,7 +231,7 @@ impl transaction_pool::Scoring<VerifiedTransaction> for Scoring {
 
 	fn update_scores(
 		&self,
-		xts: &[Transaction<VerifiedTransaction>],
+		xts: &[txpool::Transaction<VerifiedTransaction>],
 		scores: &mut [Self::Score],
 		_change: Change<()>
 	) {
@@ -276,7 +249,7 @@ impl transaction_pool::Scoring<VerifiedTransaction> for Scoring {
 /// Readiness evaluator for polkadot transactions.
 pub struct Ready<'a, T: 'a + PolkadotApi> {
 	at_block: T::CheckedBlockId,
-	api_handle: &'a T,
+	api: &'a T,
 	known_indices: HashMap<AccountId, ::primitives::Index>,
 }
 
@@ -284,7 +257,7 @@ impl<'a, T: 'a + PolkadotApi> Clone for Ready<'a, T> {
 	fn clone(&self) -> Self {
 		Ready {
 			at_block: self.at_block.clone(),
-			api_handle: self.api_handle,
+			api: self.api,
 			known_indices: self.known_indices.clone(),
 		}
 	}
@@ -293,106 +266,85 @@ impl<'a, T: 'a + PolkadotApi> Clone for Ready<'a, T> {
 impl<'a, T: 'a + PolkadotApi> Ready<'a, T> {
 	/// Create a new readiness evaluator at the given block. Requires that
 	/// the ID has already been checked for local corresponding and available state.
-	pub fn create(at: T::CheckedBlockId, client: &'a T) -> Self {
+	pub fn create(at: T::CheckedBlockId, api: &'a T) -> Self {
 		Ready {
 			at_block: at,
-			api_handle: client,
+			api,
 			known_indices: HashMap::new(),
 		}
 	}
 }
 
-impl<'a, T: 'a + PolkadotApi> transaction_pool::Ready<VerifiedTransaction> for Ready<'a, T> {
+impl<'a, T: 'a + PolkadotApi> txpool::Ready<VerifiedTransaction> for Ready<'a, T> {
 	fn is_ready(&mut self, xt: &VerifiedTransaction) -> Readiness {
 		let sender = xt.inner.signed;
 		trace!(target: "transaction-pool", "Checking readiness of {} (from {})", xt.hash, Hash::from(sender));
 
 		// TODO: find a way to handle index error properly -- will need changes to
 		// transaction-pool trait.
-		let (api_handle, at_block) = (&self.api_handle, &self.at_block);
+		let (api, at_block) = (&self.api, &self.at_block);
 		let next_index = self.known_indices.entry(sender)
-			.or_insert_with(|| api_handle.index(at_block, sender).ok().unwrap_or_else(Bounded::max_value));
+			.or_insert_with(|| api.index(at_block, sender).ok().unwrap_or_else(Bounded::max_value));
 
 		trace!(target: "transaction-pool", "Next index for sender is {}; xt index is {}", next_index, xt.inner.index);
 
-		match xt.inner.index.cmp(&next_index) {
+		let result = match xt.inner.index.cmp(&next_index) {
 			Ordering::Greater => Readiness::Future,
 			Ordering::Equal => Readiness::Ready,
-			Ordering::Less => Readiness::Stale,	// TODO: this is not "stalled" but rather stale and can be discarded.
+			Ordering::Less => Readiness::Stale,
-		}
+		};
+
+		// remember to increment `next_index`
+		*next_index = next_index.saturating_add(1);
+
+		result
+	}
+}
+
+pub struct Verifier;
+
+impl txpool::Verifier<Extrinsic> for Verifier {
+	type VerifiedTransaction = VerifiedTransaction;
+	type Error = Error;
+
+	fn verify_transaction(&self, xt: Extrinsic) -> Result<Self::VerifiedTransaction> {
+		info!("Extrinsic submitted: {}", HexDisplay::from(&xt.0));
+		let uxt = xt.using_encoded(|ref mut s| UncheckedExtrinsic::decode(s))
+			.ok_or_else(|| ErrorKind::InvalidExtrinsicFormat)?;
+		info!("Correctly formatted: {:?}", uxt);
+		VerifiedTransaction::create(uxt)
 	}
 }
 
 /// The polkadot transaction pool.
 ///
-/// Wraps a `transaction-pool::Pool`.
+/// Wraps a `extrinsic_pool::Pool`.
 pub struct TransactionPool {
-	inner: transaction_pool::Pool<VerifiedTransaction, Scoring>,
+	inner: Pool<Verifier, Scoring, Error>,
-	insertion_index: u64, // TODO: use AtomicU64 when it stabilizes
 }
 
 impl TransactionPool {
 	/// Create a new transaction pool.
 	pub fn new(options: Options) -> Self {
 		TransactionPool {
-			inner: Pool::new(NoopListener, Scoring, options),
+			inner: Pool::new(options, Verifier, Scoring),
-			insertion_index: 0,
 		}
 	}
 
-	/// Verify and import a transaction into the pool.
+	pub fn import_unchecked_extrinsic(&self, uxt: UncheckedExtrinsic) -> Result<Arc<VerifiedTransaction>> {
-	pub fn import(&mut self, xt: UncheckedExtrinsic) -> Result<Arc<VerifiedTransaction>> {
+		Ok(self.inner.import(VerifiedTransaction::create(uxt)?)?)
-		let insertion_index = self.insertion_index;
-		self.insertion_index += 1;
-
-		let verified = VerifiedTransaction::create(xt, insertion_index)?;
-
-		info!("Extrinsic verified {:?}. Importing...", verified);
-
-		// TODO: just use a foreign link when the error type is made public.
-		let hash = verified.hash.clone();
-		self.inner.import(verified)
-			.map_err(|e|
-				match e {
-					// TODO: make error types public in transaction_pool. For now just treat all errors as AlreadyImported
-					_ => ErrorKind::AlreadyImported(hash),
-					// transaction_pool::error::AlreadyImported(h) => ErrorKind::AlreadyImported(h),
-					// e => ErrorKind::Import(Box::new(e)),
-				})
-			.map_err(Into::into)
 	}
+}
 
-	/// Clear the pool.
+impl Deref for TransactionPool {
-	pub fn clear(&mut self) {
+	type Target = Pool<Verifier, Scoring, Error>;
-		self.inner.clear();
-	}
 
-	/// Remove from the pool.
+	fn deref(&self) -> &Self::Target {
-	pub fn remove(&mut self, hash: &Hash, is_valid: bool) -> Option<Arc<VerifiedTransaction>> {
+		&self.inner
-		self.inner.remove(hash, is_valid)
-	}
-
-	/// Cull transactions from the queue.
-	pub fn cull<T: PolkadotApi>(&mut self, senders: Option<&[AccountId]>, ready: Ready<T>) -> usize {
-		self.inner.cull(senders, ready)
-	}
-
-	/// Get an iterator of pending transactions.
-	pub fn pending<'a, T: 'a + PolkadotApi>(&'a self, ready: Ready<'a, T>) -> PendingIterator<'a, T> {
-		self.inner.pending(ready)
-	}
-
-	/// Get the full status of the queue (including readiness)
-	pub fn status<T: PolkadotApi>(&self, ready: Ready<T>) -> Status {
-		self.inner.status(ready)
-	}
-
-	/// Returns light status of the pool.
-	pub fn light_status(&self) -> LightStatus {
-		self.inner.light_status()
 	}
 }
 
 #[cfg(test)]
 mod tests {
 }
+

substrate/substrate/client/src/client.rs

@@ -344,7 +344,8 @@ impl<B, E> Client<B, E> where
 				header: header,
 				is_new_best: is_new_best,
 			};
-			self.import_notification_sinks.lock().retain(|sink| !sink.unbounded_send(notification.clone()).is_err());
+			self.import_notification_sinks.lock()
+				.retain(|sink| sink.unbounded_send(notification.clone()).is_ok());
 		}
 		Ok(ImportResult::Queued)
 	}

substrate/substrate/extrinsic-pool/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "substrate-extrinsic-pool"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+
+[dependencies]
+error-chain = "0.11"
+futures = "0.1"
+log = "0.3"
+parking_lot = "0.4"
+substrate-primitives = { path = "../primitives" }
+transaction-pool = "1.12"

substrate/substrate/extrinsic-pool/src/api.rs

@@ -0,0 +1,64 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! External API for extrinsic pool.
+
+use std::ops::Deref;
+use txpool::{self, VerifiedTransaction};
+use primitives::{
+	Hash,
+	block::{Extrinsic, ExtrinsicHash},
+};
+
+/// Extrinsic pool error.
+pub trait Error: ::std::error::Error + Send + Sized {
+	/// Try to extract original `txpool::Error`
+	///
+	/// This implementation is optional and used only to
+	/// provide more descriptive error messages for end users
+	/// of RPC API.
+	fn into_pool_error(self) -> Result<txpool::Error, Self> { Err(self) }
+}
+
+impl Error for txpool::Error {
+	fn into_pool_error(self) -> Result<txpool::Error, Self> { Ok(self) }
+}
+
+/// Extrinsic pool.
+pub trait ExtrinsicPool: Send + Sync + 'static {
+	/// Error type
+	type Error: Error;
+
+	/// Submit a collection of extrinsics to the pool.
+	fn submit(&self, xt: Vec<Extrinsic>) -> Result<Vec<ExtrinsicHash>, Self::Error>;
+}
+
+// Blanket implementation for anything that `Derefs` to the pool.
+impl<V, S, E, T> ExtrinsicPool for T where
+	T: Deref<Target=super::Pool<V, S, E>> + Send + Sync + 'static,
+	V: txpool::Verifier<Extrinsic>,
+	S: txpool::Scoring<V::VerifiedTransaction>,
+	V::VerifiedTransaction: txpool::VerifiedTransaction<Hash=Hash>,
+	E: From<V::Error>,
+	E: From<txpool::Error>,
+	E: Error,
+{
+	type Error = E;
+
+	fn submit(&self, xt: Vec<Extrinsic>) -> Result<Vec<ExtrinsicHash>, Self::Error> {
+		self.deref().submit(xt).map(|result| result.into_iter().map(|xt| *xt.hash()).collect())
+	}
+}

substrate/substrate/extrinsic-pool/src/lib.rs

@@ -0,0 +1,37 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+#![warn(missing_docs)]
+
+//! Generic extrinsic pool.
+
+extern crate futures;
+extern crate parking_lot;
+extern crate substrate_primitives as primitives;
+
+#[macro_use]
+extern crate log;
+
+pub extern crate transaction_pool as txpool;
+
+pub mod api;
+
+mod listener;
+mod pool;
+mod watcher;
+
+pub use self::pool::Pool;
+pub use self::watcher::Watcher;

substrate/substrate/extrinsic-pool/src/listener.rs

@@ -0,0 +1,89 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::{
+	sync::Arc,
+	collections::HashMap,
+};
+use primitives::Hash;
+use txpool;
+
+use watcher;
+
+#[derive(Default)]
+pub struct Listener {
+	watchers: HashMap<Hash, watcher::Sender>
+}
+
+impl Listener {
+	pub fn create_watcher<T: txpool::VerifiedTransaction<Hash=Hash>>(&mut self, xt: Arc<T>) -> watcher::Watcher {
+		let sender = self.watchers.entry(*xt.hash()).or_insert_with(watcher::Sender::default);
+		sender.new_watcher()
+	}
+
+	pub fn broadcasted(&mut self, hash: &Hash, peers: Vec<String>) {
+		self.fire(hash, |watcher| watcher.broadcast(peers));
+	}
+
+	fn fire<F: FnOnce(&mut watcher::Sender)>(&mut self, hash: &Hash, fun: F) {
+		let clean = if let Some(h) = self.watchers.get_mut(hash) {
+			fun(h);
+			h.is_done()
+		} else {
+			false
+		};
+
+		if clean {
+			self.watchers.remove(hash);
+		}
+	}
+}
+
+impl<T: txpool::VerifiedTransaction<Hash=Hash>> txpool::Listener<T> for Listener {
+	fn added(&mut self, tx: &Arc<T>, old: Option<&Arc<T>>) {
+		if let Some(old) = old {
+			let hash = tx.hash();
+			self.fire(old.hash(), |watcher| watcher.usurped(*hash));
+		}
+	}
+
+	fn dropped(&mut self, tx: &Arc<T>, by: Option<&T>) {
+		self.fire(tx.hash(), |watcher| match by {
+			Some(t) => watcher.usurped(*t.hash()),
+			None => watcher.dropped(),
+		})
+	}
+
+	fn rejected(&mut self, tx: &Arc<T>, reason: &txpool::ErrorKind) {
+		warn!("Extrinsic rejected ({}): {:?}", reason, tx);
+	}
+
+	fn invalid(&mut self, tx: &Arc<T>) {
+		warn!("Extrinsic invalid: {:?}", tx);
+	}
+
+	fn canceled(&mut self, tx: &Arc<T>) {
+		warn!("Extrinsic canceled: {:?}", tx);
+	}
+
+	fn mined(&mut self, tx: &Arc<T>) {
+		// TODO [ToDr] latest block number?
+		let header_hash = 1.into();
+		self.fire(tx.hash(), |watcher| watcher.finalised(header_hash))
+	}
+}
+
+

substrate/substrate/extrinsic-pool/src/pool.rs

@@ -0,0 +1,141 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::{
+	collections::HashMap,
+	marker::PhantomData,
+	sync::{Arc, Weak},
+};
+
+use futures::sync::mpsc;
+use parking_lot::{RwLock, Mutex};
+use txpool;
+use primitives::{Hash, block::Extrinsic};
+
+use listener::Listener;
+use watcher::Watcher;
+
+/// Extrinsics pool.
+pub struct Pool<V, S, E> where
+	V: txpool::Verifier<Extrinsic>,
+	S: txpool::Scoring<V::VerifiedTransaction>,
+{
+	_error: Mutex<PhantomData<E>>,
+	pool: RwLock<txpool::Pool<
+		V::VerifiedTransaction,
+		S,
+		Listener,
+	>>,
+	verifier: V,
+	import_notification_sinks: Mutex<Vec<mpsc::UnboundedSender<Weak<V::VerifiedTransaction>>>>,
+}
+
+impl<V, S, E> Pool<V, S, E> where
+	V: txpool::Verifier<Extrinsic>,
+	S: txpool::Scoring<V::VerifiedTransaction>,
+	V::VerifiedTransaction: txpool::VerifiedTransaction<Hash=Hash>,
+	E: From<V::Error>,
+	E: From<txpool::Error>,
+{
+	/// Create a new transaction pool.
+	pub fn new(options: txpool::Options, verifier: V, scoring: S) -> Self {
+		Pool {
+			_error: Default::default(),
+			pool: RwLock::new(txpool::Pool::new(Listener::default(), scoring, options)),
+			verifier,
+			import_notification_sinks: Default::default(),
+		}
+	}
+
+	/// Imports a pre-verified extrinsic to the pool.
+	pub fn import(&self, xt: V::VerifiedTransaction) -> Result<Arc<V::VerifiedTransaction>, E> {
+		let result = self.pool.write().import(xt)?;
+
+		let weak = Arc::downgrade(&result);
+		self.import_notification_sinks.lock()
+			.retain(|sink| sink.unbounded_send(weak.clone()).is_ok());
+
+		Ok(result)
+	}
+
+	/// Return an event stream of transactions imported to the pool.
+	pub fn import_notification_stream(&self) -> mpsc::UnboundedReceiver<Weak<V::VerifiedTransaction>> {
+		let (sink, stream) = mpsc::unbounded();
+		self.import_notification_sinks.lock().push(sink);
+		stream
+	}
+
+	/// Invoked when extrinsics are broadcasted.
+	pub fn on_broadcasted(&self, propagated: HashMap<Hash, Vec<String>>) {
+		for (hash, peers) in propagated.into_iter() {
+			self.pool.write().listener_mut().broadcasted(&hash, peers);
+		}
+	}
+
+	/// Imports a bunch of extrinsics to the pool
+	pub fn submit(&self, xts: Vec<Extrinsic>) -> Result<Vec<Arc<V::VerifiedTransaction>>, E> {
+		xts
+			.into_iter()
+			.map(|xt| self.verifier.verify_transaction(xt))
+			.map(|xt| {
+				Ok(self.pool.write().import(xt?)?)
+			})
+			.collect()
+	}
+
+	/// Import a single extrinsic and starts to watch their progress in the pool.
+	pub fn submit_and_watch(&self, xt: Extrinsic) -> Result<Watcher, E> {
+		let xt = self.submit(vec![xt])?.pop().expect("One extrinsic passed; one result returned; qed");
+		Ok(self.pool.write().listener_mut().create_watcher(xt))
+	}
+
+	/// Remove from the pool.
+	pub fn remove(&self, hashes: &[Hash], is_valid: bool) -> Vec<Option<Arc<V::VerifiedTransaction>>> {
+		let mut pool = self.pool.write();
+		let mut results = Vec::with_capacity(hashes.len());
+		for hash in hashes {
+			results.push(pool.remove(hash, is_valid));
+		}
+		results
+	}
+
+	/// Cull transactions from the queue.
+	pub fn cull<R>(&self, senders: Option<&[<V::VerifiedTransaction as txpool::VerifiedTransaction>::Sender]>, ready: R) -> usize where
+		R: txpool::Ready<V::VerifiedTransaction>,
+	{
+		self.pool.write().cull(senders, ready)
+	}
+
+	/// Cull transactions from the queue and then compute the pending set.
+	pub fn cull_and_get_pending<R, F, T>(&self, ready: R, f: F) -> T where
+		R: txpool::Ready<V::VerifiedTransaction> + Clone,
+		F: FnOnce(txpool::PendingIterator<V::VerifiedTransaction, R, S, Listener>) -> T,
+	{
+		let mut pool = self.pool.write();
+		pool.cull(None, ready.clone());
+		f(pool.pending(ready))
+	}
+
+	/// Get the full status of the queue (including readiness)
+	pub fn status<R: txpool::Ready<V::VerifiedTransaction>>(&self, ready: R) -> txpool::Status {
+		self.pool.read().status(ready)
+	}
+
+	/// Returns light status of the pool.
+	pub fn light_status(&self) -> txpool::LightStatus {
+		self.pool.read().light_status()
+	}
+}

substrate/substrate/extrinsic-pool/src/watcher.rs

@@ -0,0 +1,88 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use futures::sync::mpsc;
+use primitives::{
+	block::{HeaderHash, ExtrinsicHash}
+};
+
+/// Possible extrinsic status events
+#[derive(Debug, Clone)]
+pub enum Status {
+	/// Extrinsic has been finalised in block with given hash.
+	Finalised(HeaderHash),
+	/// Some state change (perhaps another extrinsic was included) rendered this extrinsic invalid.
+	Usurped(ExtrinsicHash),
+	/// The extrinsic has been broadcast to the given peers.
+	Broadcast(Vec<String>),
+	/// Extrinsic has been dropped from the pool because of the limit.
+	Dropped,
+}
+
+/// Extrinsic watcher.
+///
+/// Represents a stream of status updates for particular extrinsic.
+#[derive(Debug)]
+pub struct Watcher {
+	receiver: mpsc::UnboundedReceiver<Status>,
+}
+
+#[derive(Debug, Default)]
+pub(crate) struct Sender {
+	receivers: Vec<mpsc::UnboundedSender<Status>>,
+	finalised: bool,
+}
+
+impl Sender {
+	/// Add a new watcher to this sender object.
+	pub fn new_watcher(&mut self) -> Watcher {
+		let (tx, receiver) = mpsc::unbounded();
+		self.receivers.push(tx);
+		Watcher {
+			receiver,
+		}
+	}
+
+	/// Some state change (perhaps another extrinsic was included) rendered this extrinsic invalid.
+	pub fn usurped(&mut self, hash: ExtrinsicHash) {
+		self.send(Status::Usurped(hash))
+	}
+
+	/// Extrinsic has been finalised in block with given hash.
+	pub fn finalised(&mut self, hash: HeaderHash) {
+		self.send(Status::Finalised(hash));
+		self.finalised = true;
+	}
+
+	/// Transaction has been dropped from the pool because of the limit.
+	pub fn dropped(&mut self) {
+		self.send(Status::Dropped);
+	}
+
+	/// The extrinsic has been broadcast to the given peers.
+	pub fn broadcast(&mut self, peers: Vec<String>) {
+		self.send(Status::Broadcast(peers))
+	}
+
+	/// Returns true if the are no more listeners for this extrinsic or it was finalised.
+	pub fn is_done(&self) -> bool {
+		self.finalised || self.receivers.is_empty()
+	}
+
+	fn send(&mut self, status: Status) {
+		self.receivers.retain(|sender| sender.unbounded_send(status.clone()).is_ok())
+	}
+}

substrate/substrate/network/src/protocol.rs

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.?
 
-use std::collections::{HashMap, HashSet, BTreeMap};
+use std::collections::{HashMap, HashSet};
 use std::{mem, cmp};
 use std::sync::Arc;
 use std::time;
@@ -24,7 +24,7 @@ use serde_json;
 use primitives::block::{HeaderHash, ExtrinsicHash, Number as BlockNumber, Header, Id as BlockId};
 use primitives::{Hash, blake2_256};
 use runtime_support::Hashable;
-use network::{PeerId, NodeId};
+use network::PeerId;
 
 use message::{self, Message};
 use sync::{ChainSync, Status as SyncStatus, SyncState};
@@ -103,15 +103,6 @@ pub struct PeerInfo {
 	pub best_number: BlockNumber,
 }
 
-/// Transaction stats
-#[derive(Debug)]
-pub struct TransactionStats {
-	/// Block number where this TX was first seen.
-	pub first_seen: u64,
-	/// Peers it was propagated to.
-	pub propagated_to: BTreeMap<NodeId, usize>,
-}
-
 impl Protocol {
 	/// Create a new instance.
 	pub fn new(config: ProtocolConfig, chain: Arc<Client>, on_demand: Option<Arc<OnDemandService>>, transaction_pool: Arc<TransactionPool>) -> error::Result<Protocol>  {
@@ -463,15 +454,31 @@ impl Protocol {
 
 		let transactions = self.transaction_pool.transactions();
 
+		let mut propagated_to = HashMap::new();
 		let mut peers = self.peers.write();
 		for (peer_id, ref mut peer) in peers.iter_mut() {
-			let to_send: Vec<_> = transactions.iter().filter_map(|&(hash, ref t)|
+			let (hashes, to_send): (Vec<_>, Vec<_>) = transactions
-				if peer.known_transactions.insert(hash.clone()) { Some(t.clone()) } else { None }).collect();
+				.iter()
+				.cloned()
+				.filter(|&(hash, _)| peer.known_transactions.insert(hash))
+				.unzip();
+
 			if !to_send.is_empty() {
+				let node_id = io.peer_session_info(*peer_id).map(|info| match info.id {
+					Some(id) => format!("{}@{:x}", info.remote_address, id),
+					None => info.remote_address.clone(),
+				});
+
+				if let Some(id) = node_id {
+					for hash in hashes {
+						propagated_to.entry(hash).or_insert_with(Vec::new).push(id.clone());
+					}
+				}
 				trace!(target: "sync", "Sending {} transactions to {}", to_send.len(), peer_id);
 				self.send_message(io, *peer_id, Message::Transactions(to_send));
 			}
 		}
+		self.transaction_pool.on_broadcasted(propagated_to);
 	}
 
 	/// Send Status message
@@ -551,10 +558,6 @@ impl Protocol {
 		self.on_demand.as_ref().map(|s| s.on_remote_response(io, peer_id, response));
 	}
 
-	pub fn transactions_stats(&self) -> BTreeMap<ExtrinsicHash, TransactionStats> {
-		BTreeMap::new()
-	}
-
 	pub fn chain(&self) -> &Client {
 		&*self.chain
 	}

substrate/substrate/network/src/service.rs

@@ -14,8 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.?
 
+use std::collections::HashMap;
 use std::sync::Arc;
-use std::collections::{BTreeMap};
 use std::io;
 use std::time::Duration;
 use futures::sync::{oneshot, mpsc};
@@ -26,7 +26,7 @@ use primitives::block::{ExtrinsicHash, Header, HeaderHash};
 use primitives::Hash;
 use core_io::{TimerToken};
 use io::NetSyncIo;
-use protocol::{Protocol, ProtocolStatus, PeerInfo as ProtocolPeerInfo, TransactionStats};
+use protocol::{Protocol, ProtocolStatus, PeerInfo as ProtocolPeerInfo};
 use config::{ProtocolConfig};
 use error::Error;
 use chain::Client;
@@ -75,8 +75,6 @@ pub trait SyncProvider: Send + Sync {
 	fn peers(&self) -> Vec<PeerInfo>;
 	/// Get this node id if available.
 	fn node_id(&self) -> Option<String>;
-	/// Returns propagation count for pending transactions.
-	fn transactions_stats(&self) -> BTreeMap<ExtrinsicHash, TransactionStats>;
 }
 
 /// Transaction pool interface
@@ -85,6 +83,8 @@ pub trait TransactionPool: Send + Sync {
 	fn transactions(&self) -> Vec<(ExtrinsicHash, Vec<u8>)>;
 	/// Import a transction into the pool.
 	fn import(&self, transaction: &[u8]) -> Option<ExtrinsicHash>;
+	/// Notify the pool about transactions broadcast.
+	fn on_broadcasted(&self, propagations: HashMap<ExtrinsicHash, Vec<String>>);
 }
 
 /// ConsensusService
@@ -249,10 +249,6 @@ impl SyncProvider for Service {
 	fn node_id(&self) -> Option<String> {
 		self.network.external_url()
 	}
-
-	fn transactions_stats(&self) -> BTreeMap<ExtrinsicHash, TransactionStats> {
-		self.handler.protocol.transactions_stats()
-	}
 }
 
 /// ConsensusService

substrate/substrate/network/src/test/mod.rs

@@ -204,6 +204,8 @@ impl TransactionPool for EmptyTransactionPool {
 	fn import(&self, _transaction: &[u8]) -> Option<ExtrinsicHash> {
 		None
 	}
+
+	fn on_broadcasted(&self, _: HashMap<ExtrinsicHash, Vec<String>>) {}
 }
 
 pub struct TestNet {

substrate/substrate/rpc/Cargo.toml

@@ -12,6 +12,7 @@ log = "0.3"
 parking_lot = "0.4"
 substrate-client = { path = "../client" }
 substrate-executor = { path = "../executor" }
+substrate-extrinsic-pool = { path = "../extrinsic-pool" }
 substrate-primitives = { path = "../primitives" }
 substrate-state-machine = { path = "../state-machine" }
 tokio-core = "0.1.12"

substrate/substrate/rpc/src/author/error.rs

@@ -16,12 +16,12 @@
 
 //! Authoring RPC module errors.
 
-use client;
+use extrinsic_pool::txpool;
 use rpc;
 
 error_chain! {
 	links {
-		Client(client::error::Error, client::error::ErrorKind) #[doc = "Client error"];
+		Pool(txpool::Error, txpool::ErrorKind) #[doc = "Pool error"];
 	}
 	errors {
 		/// Not implemented yet
@@ -29,15 +29,10 @@ error_chain! {
 			description("not yet implemented"),
 			display("Method Not Implemented"),
 		}
-		/// Invalid format
+		/// Verification error
-		InvalidFormat {
+		Verification(e: Box<::std::error::Error + Send>) {
-			description("invalid format"),
+			description("extrinsic verification error"),
-			display("Invalid format for the extrinsic data"),
+			display("Extrinsic verification error: {}", e.description()),
-		}
-		/// Some error with the pool since the import failed.
-		PoolError {
-			description("pool import failed"),
-			display("Pool import failed"),
 		}
 	}
 }
@@ -50,6 +45,7 @@ impl From<Error> for rpc::Error {
 				message: "Not implemented yet".into(),
 				data: None,
 			},
+			// TODO [ToDr] Unwrap Pool errors.
 			_ => rpc::Error::internal_error(),
 		}
 	}

substrate/substrate/rpc/src/author/mod.rs

@@ -16,7 +16,9 @@
 
 //! Substrate block-author/full-node API.
 
-use primitives::block::Extrinsic;
+use std::sync::Arc;
+use primitives::block::{Extrinsic, ExtrinsicHash};
+use extrinsic_pool::api::{Error, ExtrinsicPool};
 
 pub mod error;
 
@@ -30,6 +32,20 @@ build_rpc_trait! {
 	pub trait AuthorApi {
 		/// Submit extrinsic for inclusion in block.
 		#[rpc(name = "author_submitExtrinsic")]
-		fn submit_extrinsic(&self, Extrinsic) -> Result<()>;
+		fn submit_extrinsic(&self, Extrinsic) -> Result<ExtrinsicHash>;
+	}
+}
+
+impl<T> AuthorApi for Arc<T> where
+	T: ExtrinsicPool,
+{
+	fn submit_extrinsic(&self, xt: Extrinsic) -> Result<ExtrinsicHash> {
+		self
+			.submit(vec![xt])
+			.map(|mut res| res.pop().expect("One extrinsic passed; one result back; qed"))
+			.map_err(|e| e.into_pool_error()
+				.map(Into::into)
+				.unwrap_or_else(|e| error::ErrorKind::Verification(Box::new(e)).into())
+			)
 	}
 }

substrate/substrate/rpc/src/author/tests.rs

@@ -15,37 +15,53 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 use super::*;
-use super::error::*;
 
-use std::sync::Arc;
+use std::{fmt, sync::Arc};
+use extrinsic_pool::api;
 use parking_lot::Mutex;
 use primitives::block;
 
 #[derive(Default)]
 struct DummyTxPool {
-	submitted: Vec<block::Extrinsic>,
+	submitted: Mutex<Vec<block::Extrinsic>>,
 }
 
-impl AuthorApi for Arc<Mutex<DummyTxPool>> {
+#[derive(Debug)]
+struct Error;
+impl api::Error for Error {}
+impl ::std::error::Error for Error {
+	fn description(&self) -> &str { "Error" }
+}
+impl fmt::Display for Error {
+	fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+		fmt::Debug::fmt(self, fmt)
+	}
+}
+
+impl api::ExtrinsicPool for DummyTxPool {
+	type Error = Error;
+
 	/// Submit extrinsic for inclusion in block.
-	fn submit_extrinsic(&self, xt: Extrinsic) -> Result<()> {
+	fn submit(&self, xt: Vec<Extrinsic>) -> ::std::result::Result<Vec<ExtrinsicHash>, Self::Error> {
-		let mut s = self.lock();
+		let mut submitted = self.submitted.lock();
-		if s.submitted.len() < 1 {
+		if submitted.len() < 1 {
-			s.submitted.push(xt);
+			let hashes = xt.iter().map(|_xt| 1.into()).collect();
-			Ok(())
+			submitted.extend(xt);
+			Ok(hashes)
 		} else {
-			Err(ErrorKind::PoolError.into())
+			Err(Error)
 		}
 	}
 }
 
 #[test]
 fn submit_transaction_should_not_cause_error() {
-	let p = Arc::new(Mutex::new(DummyTxPool::default()));
+	let p = Arc::new(DummyTxPool::default());
+	let hash: ExtrinsicHash = 1.into();
 
 	assert_matches!(
 		AuthorApi::submit_extrinsic(&p, block::Extrinsic(vec![])),
-		Ok(())
+		Ok(hash)
 	);
 	assert!(
 		AuthorApi::submit_extrinsic(&p, block::Extrinsic(vec![])).is_err()

substrate/substrate/rpc/src/lib.rs

@@ -22,6 +22,7 @@ extern crate jsonrpc_core as rpc;
 extern crate jsonrpc_pubsub;
 extern crate parking_lot;
 extern crate substrate_client as client;
+extern crate substrate_extrinsic_pool as extrinsic_pool;
 extern crate substrate_primitives as primitives;
 extern crate substrate_state_machine as state_machine;
 extern crate tokio_core;