Squashed 'bridges/' changes from b2099c5..23dda62 (#3369)

23dda62 Rococo <> Wococo messages relay (#1030)
bcde21d Update the wasm builder to substrate master (#1029)
a8318ce Make target signer optional when sending message. (#1018)
f8602e1 Fix insufficient balance when send message. (#1020)
d95c0a7 greedy relayer don't need message dispatch to be prepaid if dispatch is supposed to be paid at the target chain (#1016)
ad5876f Update types. (#1027)
116cbbc CI: fix starting the pipeline (#1022)
7e0fadd Add temporary `canary` job (#1019)
6787091 Update types to contain dispatch_fee_payment (#1017)
03f79ad Allow Root to assume SourceAccount. (#1011)
372d019 Return dispatch_fee_payment from message details RPC (#1014)
604eb1c Relay basic single-bit message dispatch results back to the source chain (#935)
bf52fff Use plain source_queue view when selecting nonces for delivery (#1010)
fc5cf7d pay dispatch fee at target chain (#911)
1e35477 Bump Substrate to `286d7ce` (#1006)
7ad07b3 Add --only-mandatory-headers mode (#1004)
5351dc9 Messages relayer operating mode (#995)
9bc29a7 Rococo <> Wococo relayer balance guard (#998)
bc17341 rename messages_dispatch_weight -> message_details (#996)
95be244 Bump Rococo and Wococo spec versions (#999)
c35567b Move ChainWithBalances::NativeBalance -> Chain::Balance (#990)
1bfece1 Fix some nits (#988)
334ea0f Increase pause before starting relays again (#989)
7fb8248 Fix clippy in test code (#993)
d60ae50 fix clippy issues (#991)
75ca813 Make sure GRANDPA shares state with RPC. (#987)
da2a38a Bump Substrate (#986)
5a9862f Update submit finality proof weight formula (#981)
69df513 Flag for rejecting all outbound messages (#982)
14d0506 Add script to setup bench machine. (#984)
e74e8ab Move CI from GitHub Actions to GitLab (#814)
c5ca5dd Custom justification verification (#979)
643f10d Always run on-demand headers relay in complex relay (#975)
a35b0ef Add JSON type definitions for Rococo<>Wococo bridge (#977)
0eb83f2 Update cargo.deny (#980)
e1d1f4c Bump Rococo/Wococo spec_version (#976)
deac90d increase pause before starting relays (#974)
68d6d79 Revert to use InspectCmd, bump substrate `6bef4f4` (#966)
66e1508 Avoid hashing headers twice in verify_justification (#973)
a31844f Bump `environmental` dependency (#972)
2a4c29a in auto-relays keep trying to connect to nodes until connection is established (#971)
0e767b3 removed stray file (#969)
b9545dc Serve multiple lanes with single complex relay instance (#964)
73419f4 Correct type error (#968)
bac256f Start finality relay spec-version guards for Rococo <> Wococo finality relays (#965)
bfd7037 pass source and target chain ids to account_ownership_proof (#963)
8436073 Upstream changes from Polkadot repo (#961)
e58d851 Increase account endowment amount (#960)

git-subtree-dir: bridges
git-subtree-split: 23dda6248236b27f20d76cbedc30e189cc6f736c

polkadot/bridges/relays/client-substrate/src/finality_source.rs

@@ -21,6 +21,7 @@ use crate::client::Client;
 use crate::error::Error;
 use crate::sync_header::SyncHeader;
 
+use async_std::sync::{Arc, Mutex};
 use async_trait::async_trait;
 use bp_header_chain::justification::GrandpaJustification;
 use codec::Decode;
@@ -30,26 +31,46 @@ use relay_utils::relay_loop::Client as RelayClient;
 use sp_runtime::traits::Header as HeaderT;
 use std::{marker::PhantomData, pin::Pin};
 
+/// Shared updatable reference to the maximal header number that we want to sync from the source.
+pub type RequiredHeaderNumberRef<C> = Arc<Mutex<<C as bp_runtime::Chain>::BlockNumber>>;
+
 /// Substrate node as finality source.
 pub struct FinalitySource<C: Chain, P> {
 	client: Client<C>,
+	maximal_header_number: Option<RequiredHeaderNumberRef<C>>,
 	_phantom: PhantomData<P>,
 }
 
 impl<C: Chain, P> FinalitySource<C, P> {
 	/// Create new headers source using given client.
-	pub fn new(client: Client<C>) -> Self {
+	pub fn new(client: Client<C>, maximal_header_number: Option<RequiredHeaderNumberRef<C>>) -> Self {
 		FinalitySource {
 			client,
+			maximal_header_number,
 			_phantom: Default::default(),
 		}
 	}
+
+	/// Returns reference to the underlying RPC client.
+	pub fn client(&self) -> &Client<C> {
+		&self.client
+	}
+
+	/// Returns best finalized block number.
+	pub async fn on_chain_best_finalized_block_number(&self) -> Result<C::BlockNumber, Error> {
+		// we **CAN** continue to relay finality proofs if source node is out of sync, because
+		// target node may be missing proofs that are already available at the source
+		let finalized_header_hash = self.client.best_finalized_header_hash().await?;
+		let finalized_header = self.client.header_by_hash(finalized_header_hash).await?;
+		Ok(*finalized_header.number())
+	}
 }
 
 impl<C: Chain, P> Clone for FinalitySource<C, P> {
 	fn clone(&self) -> Self {
 		FinalitySource {
 			client: self.client.clone(),
+			maximal_header_number: self.maximal_header_number.clone(),
 			_phantom: Default::default(),
 		}
 	}
@@ -80,11 +101,16 @@ where
 	type FinalityProofsStream = Pin<Box<dyn Stream<Item = GrandpaJustification<C::Header>> + Send>>;
 
 	async fn best_finalized_block_number(&self) -> Result<P::Number, Error> {
-		// we **CAN** continue to relay finality proofs if source node is out of sync, because
-		// target node may be missing proofs that are already available at the source
-		let finalized_header_hash = self.client.best_finalized_header_hash().await?;
-		let finalized_header = self.client.header_by_hash(finalized_header_hash).await?;
-		Ok(*finalized_header.number())
+		let mut finalized_header_number = self.on_chain_best_finalized_block_number().await?;
+		// never return block number larger than requested. This way we'll never sync headers
+		// past `maximal_header_number`
+		if let Some(ref maximal_header_number) = self.maximal_header_number {
+			let maximal_header_number = *maximal_header_number.lock().await;
+			if finalized_header_number > maximal_header_number {
+				finalized_header_number = maximal_header_number;
+			}
+		}
+		Ok(finalized_header_number)
 	}
 
 	async fn header_and_finality_proof(