Introduce MessagesLaneManager (#2227)

* some useful stuff like LanesManager

* clippy

* more clippy

* Error::LanesManager

* {in, out}bound_lane -> active_{in, out}bound_lane

* merge two impl blocks in one

* fmt

bridges/modules/messages/src/inbound_lane.rs

@@ -20,8 +20,8 @@ use crate::{BridgedChainOf, Config};
 
 use bp_messages::{
 	target_chain::{DispatchMessage, DispatchMessageData, MessageDispatch},
-	ChainWithMessages, DeliveredMessages, InboundLaneData, LaneId, MessageKey, MessageNonce,
-	OutboundLaneData, ReceptionResult, UnrewardedRelayer,
+	ChainWithMessages, DeliveredMessages, InboundLaneData, LaneId, LaneState, MessageKey,
+	MessageNonce, OutboundLaneData, ReceptionResult, UnrewardedRelayer,
 };
 use bp_runtime::AccountIdOf;
 use codec::{Decode, Encode, EncodeLike, MaxEncodedLen};
@@ -44,6 +44,8 @@ pub trait InboundLaneStorage {
 	fn data(&self) -> InboundLaneData<Self::Relayer>;
 	/// Update lane data in the storage.
 	fn set_data(&mut self, data: InboundLaneData<Self::Relayer>);
+	/// Purge lane data from the storage.
+	fn purge(self);
 }
 
 /// Inbound lane data wrapper that implements `MaxEncodedLen`.
@@ -120,9 +122,21 @@ impl<S: InboundLaneStorage> InboundLane<S> {
 		InboundLane { storage }
 	}
 
-	/// Returns `mut` storage reference.
-	pub fn storage_mut(&mut self) -> &mut S {
-		&mut self.storage
+	/// Get lane state.
+	pub fn state(&self) -> LaneState {
+		self.storage.data().state
+	}
+
+	/// Returns storage reference.
+	pub fn storage(&self) -> &S {
+		&self.storage
+	}
+
+	/// Set lane state.
+	pub fn set_state(&mut self, state: LaneState) {
+		let mut data = self.storage.data();
+		data.state = state;
+		self.storage.set_data(data);
 	}
 
 	/// Receive state of the corresponding outbound lane.
@@ -211,12 +225,17 @@ impl<S: InboundLaneStorage> InboundLane<S> {
 
 		ReceptionResult::Dispatched(dispatch_result)
 	}
+
+	/// Purge lane state from the storage.
+	pub fn purge(self) {
+		self.storage.purge()
+	}
 }
 
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use crate::{inbound_lane, tests::mock::*, RuntimeInboundLaneStorage};
+	use crate::{inbound_lane, lanes_manager::RuntimeInboundLaneStorage, tests::mock::*};
 	use bp_messages::UnrewardedRelayersState;
 
 	fn receive_regular_message(

bridges/modules/messages/src/lanes_manager.rs

@@ -0,0 +1,263 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common 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 Bridges Common 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 Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+use crate::{
+	BridgedChainOf, Config, InboundLane, InboundLaneStorage, InboundLanes, OutboundLane,
+	OutboundLaneStorage, OutboundLanes, OutboundMessages, StoredInboundLaneData,
+	StoredMessagePayload,
+};
+
+use bp_messages::{
+	ChainWithMessages, InboundLaneData, LaneId, LaneState, MessageKey, MessageNonce,
+	OutboundLaneData,
+};
+use bp_runtime::AccountIdOf;
+use codec::{Decode, Encode, MaxEncodedLen};
+use frame_support::{ensure, sp_runtime::RuntimeDebug, PalletError};
+use scale_info::TypeInfo;
+use sp_std::marker::PhantomData;
+
+/// Lanes manager errors.
+#[derive(Encode, Decode, RuntimeDebug, PartialEq, Eq, PalletError, TypeInfo)]
+pub enum LanesManagerError {
+	/// Inbound lane already exists.
+	InboundLaneAlreadyExists,
+	/// Outbound lane already exists.
+	OutboundLaneAlreadyExists,
+	/// No inbound lane with given id.
+	UnknownInboundLane,
+	/// No outbound lane with given id.
+	UnknownOutboundLane,
+	/// Inbound lane with given id is closed.
+	ClosedInboundLane,
+	/// Outbound lane with given id is closed.
+	ClosedOutboundLane,
+}
+
+/// Message lanes manager.
+pub struct LanesManager<T, I>(PhantomData<(T, I)>);
+
+impl<T: Config<I>, I: 'static> Default for LanesManager<T, I> {
+	fn default() -> Self {
+		Self::new()
+	}
+}
+
+impl<T: Config<I>, I: 'static> LanesManager<T, I> {
+	/// Create new lanes manager.
+	pub fn new() -> Self {
+		Self(PhantomData)
+	}
+
+	/// Create new inbound lane in `Opened` state.
+	pub fn create_inbound_lane(
+		&self,
+		lane_id: LaneId,
+	) -> Result<InboundLane<RuntimeInboundLaneStorage<T, I>>, LanesManagerError> {
+		InboundLanes::<T, I>::try_mutate(lane_id, |lane| match lane {
+			Some(_) => Err(LanesManagerError::InboundLaneAlreadyExists),
+			None => {
+				*lane = Some(StoredInboundLaneData(InboundLaneData {
+					state: LaneState::Opened,
+					..Default::default()
+				}));
+				Ok(())
+			},
+		})?;
+
+		self.active_inbound_lane(lane_id)
+	}
+
+	/// Create new outbound lane in `Opened` state.
+	pub fn create_outbound_lane(
+		&self,
+		lane_id: LaneId,
+	) -> Result<OutboundLane<RuntimeOutboundLaneStorage<T, I>>, LanesManagerError> {
+		OutboundLanes::<T, I>::try_mutate(lane_id, |lane| match lane {
+			Some(_) => Err(LanesManagerError::OutboundLaneAlreadyExists),
+			None => {
+				*lane = Some(OutboundLaneData { state: LaneState::Opened, ..Default::default() });
+				Ok(())
+			},
+		})?;
+
+		self.active_outbound_lane(lane_id)
+	}
+
+	/// Get existing inbound lane, checking that it is in usable state.
+	pub fn active_inbound_lane(
+		&self,
+		lane_id: LaneId,
+	) -> Result<InboundLane<RuntimeInboundLaneStorage<T, I>>, LanesManagerError> {
+		Ok(InboundLane::new(RuntimeInboundLaneStorage::from_lane_id(lane_id, true)?))
+	}
+
+	/// Get existing outbound lane, checking that it is in usable state.
+	pub fn active_outbound_lane(
+		&self,
+		lane_id: LaneId,
+	) -> Result<OutboundLane<RuntimeOutboundLaneStorage<T, I>>, LanesManagerError> {
+		Ok(OutboundLane::new(RuntimeOutboundLaneStorage::from_lane_id(lane_id, true)?))
+	}
+
+	/// Get existing inbound lane without any additional state checks.
+	pub fn any_state_inbound_lane(
+		&self,
+		lane_id: LaneId,
+	) -> Result<InboundLane<RuntimeInboundLaneStorage<T, I>>, LanesManagerError> {
+		Ok(InboundLane::new(RuntimeInboundLaneStorage::from_lane_id(lane_id, false)?))
+	}
+
+	/// Get existing outbound lane without any additional state checks.
+	pub fn any_state_outbound_lane(
+		&self,
+		lane_id: LaneId,
+	) -> Result<OutboundLane<RuntimeOutboundLaneStorage<T, I>>, LanesManagerError> {
+		Ok(OutboundLane::new(RuntimeOutboundLaneStorage::from_lane_id(lane_id, false)?))
+	}
+}
+
+/// Runtime inbound lane storage.
+pub struct RuntimeInboundLaneStorage<T: Config<I>, I: 'static = ()> {
+	pub(crate) lane_id: LaneId,
+	pub(crate) cached_data: InboundLaneData<AccountIdOf<BridgedChainOf<T, I>>>,
+	pub(crate) _phantom: PhantomData<I>,
+}
+
+impl<T: Config<I>, I: 'static> RuntimeInboundLaneStorage<T, I> {
+	/// Creates new runtime inbound lane storage for given **existing** lane.
+	fn from_lane_id(
+		lane_id: LaneId,
+		check_active: bool,
+	) -> Result<RuntimeInboundLaneStorage<T, I>, LanesManagerError> {
+		let cached_data =
+			InboundLanes::<T, I>::get(lane_id).ok_or(LanesManagerError::UnknownInboundLane)?;
+		ensure!(
+			!check_active || cached_data.state.is_active(),
+			LanesManagerError::ClosedInboundLane
+		);
+		Ok(RuntimeInboundLaneStorage {
+			lane_id,
+			cached_data: cached_data.into(),
+			_phantom: Default::default(),
+		})
+	}
+
+	/// Returns number of bytes that may be subtracted from the PoV component of
+	/// `receive_messages_proof` call, because the actual inbound lane state is smaller than the
+	/// maximal configured.
+	///
+	/// Maximal inbound lane state set size is configured by the
+	/// `MAX_UNREWARDED_RELAYERS_IN_CONFIRMATION_TX` constant from the pallet configuration. The PoV
+	/// of the call includes the maximal size of inbound lane state. If the actual size is smaller,
+	/// we may subtract extra bytes from this component.
+	pub fn extra_proof_size_bytes(&self) -> u64 {
+		let max_encoded_len = StoredInboundLaneData::<T, I>::max_encoded_len();
+		let relayers_count = self.data().relayers.len();
+		let actual_encoded_len =
+			InboundLaneData::<AccountIdOf<BridgedChainOf<T, I>>>::encoded_size_hint(relayers_count)
+				.unwrap_or(usize::MAX);
+		max_encoded_len.saturating_sub(actual_encoded_len) as _
+	}
+}
+
+impl<T: Config<I>, I: 'static> InboundLaneStorage for RuntimeInboundLaneStorage<T, I> {
+	type Relayer = AccountIdOf<BridgedChainOf<T, I>>;
+
+	fn id(&self) -> LaneId {
+		self.lane_id
+	}
+
+	fn max_unrewarded_relayer_entries(&self) -> MessageNonce {
+		BridgedChainOf::<T, I>::MAX_UNREWARDED_RELAYERS_IN_CONFIRMATION_TX
+	}
+
+	fn max_unconfirmed_messages(&self) -> MessageNonce {
+		BridgedChainOf::<T, I>::MAX_UNCONFIRMED_MESSAGES_IN_CONFIRMATION_TX
+	}
+
+	fn data(&self) -> InboundLaneData<AccountIdOf<BridgedChainOf<T, I>>> {
+		self.cached_data.clone()
+	}
+
+	fn set_data(&mut self, data: InboundLaneData<AccountIdOf<BridgedChainOf<T, I>>>) {
+		self.cached_data = data.clone();
+		InboundLanes::<T, I>::insert(self.lane_id, StoredInboundLaneData::<T, I>(data))
+	}
+
+	fn purge(self) {
+		InboundLanes::<T, I>::remove(self.lane_id)
+	}
+}
+
+/// Runtime outbound lane storage.
+#[derive(Debug, PartialEq, Eq)]
+pub struct RuntimeOutboundLaneStorage<T, I = ()> {
+	pub(crate) lane_id: LaneId,
+	pub(crate) cached_data: OutboundLaneData,
+	pub(crate) _phantom: PhantomData<(T, I)>,
+}
+
+impl<T: Config<I>, I: 'static> RuntimeOutboundLaneStorage<T, I> {
+	/// Creates new runtime outbound lane storage for given **existing** lane.
+	fn from_lane_id(lane_id: LaneId, check_active: bool) -> Result<Self, LanesManagerError> {
+		let cached_data =
+			OutboundLanes::<T, I>::get(lane_id).ok_or(LanesManagerError::UnknownOutboundLane)?;
+		ensure!(
+			!check_active || cached_data.state.is_active(),
+			LanesManagerError::ClosedOutboundLane
+		);
+		Ok(Self { lane_id, cached_data, _phantom: PhantomData })
+	}
+}
+
+impl<T: Config<I>, I: 'static> OutboundLaneStorage for RuntimeOutboundLaneStorage<T, I> {
+	type StoredMessagePayload = StoredMessagePayload<T, I>;
+
+	fn id(&self) -> LaneId {
+		self.lane_id
+	}
+
+	fn data(&self) -> OutboundLaneData {
+		self.cached_data.clone()
+	}
+
+	fn set_data(&mut self, data: OutboundLaneData) {
+		self.cached_data = data.clone();
+		OutboundLanes::<T, I>::insert(self.lane_id, data)
+	}
+
+	#[cfg(test)]
+	fn message(&self, nonce: &MessageNonce) -> Option<Self::StoredMessagePayload> {
+		OutboundMessages::<T, I>::get(MessageKey { lane_id: self.lane_id, nonce: *nonce })
+			.map(Into::into)
+	}
+
+	fn save_message(&mut self, nonce: MessageNonce, message_payload: Self::StoredMessagePayload) {
+		OutboundMessages::<T, I>::insert(
+			MessageKey { lane_id: self.lane_id, nonce },
+			message_payload,
+		);
+	}
+
+	fn remove_message(&mut self, nonce: &MessageNonce) {
+		OutboundMessages::<T, I>::remove(MessageKey { lane_id: self.lane_id, nonce: *nonce });
+	}
+
+	fn purge(self) {
+		OutboundLanes::<T, I>::remove(self.lane_id)
+	}
+}