Update SpvClient to not use Deref

Author: jkczyz

lightning-block-sync/src/init.rs

@@ -92,8 +92,9 @@ use lightning::chain;
 /// 	chain_monitor.watch_channel(monitor.get_funding_txo().0, monitor);
 ///
 /// 	let chain_poller = poll::ChainPoller::new(block_source, Network::Bitcoin);
-/// 	let mut chain_listener = (chain_monitor, &manager);
-/// 	let spv_client = SpvClient::new(chain_tip, chain_poller, &mut cache, &chain_listener);
+/// 	//let mut chain_listener = (chain_monitor, &manager);
+/// 	let chain_listener = std::rc::Rc::new(manager);
+/// 	let spv_client = SpvClient::new(chain_tip, chain_poller, &mut cache, chain_listener);
 /// }
 /// ```
 ///

lightning-block-sync/src/lib.rs

@@ -159,8 +159,7 @@ pub struct BlockHeaderData {
 /// custom cache eviction policy. This offers flexibility to those sensitive to resource usage.
 /// Hence, there is a trade-off between a lower memory footprint and potentially increased network
 /// I/O as headers are re-fetched during fork detection.
-pub struct SpvClient<'a, P: Poll, C: Cache, L: Deref>
-where L::Target: chain::Listen {
+pub struct SpvClient<'a, P: Poll, C: Cache, L: chain::Listen> {
 	chain_tip: ValidatedBlockHeader,
 	chain_poller: P,
 	chain_notifier: ChainNotifier<'a, C, L>,
@@ -208,7 +207,7 @@ impl Cache for UnboundedCache {
 	}
 }
 
-impl<'a, P: Poll, C: Cache, L: Deref> SpvClient<'a, P, C, L> where L::Target: chain::Listen {
+impl<'a, P: Poll, C: Cache, L: chain::Listen> SpvClient<'a, P, C, L> {
 	/// Creates a new SPV client using `chain_tip` as the best known chain tip.
 	///
 	/// Subsequent calls to [`poll_best_tip`] will poll for the best chain tip using the given chain
@@ -272,7 +271,7 @@ impl<'a, P: Poll, C: Cache, L: Deref> SpvClient<'a, P, C, L> where L::Target: ch
 /// Notifies [listeners] of blocks that have been connected or disconnected from the chain.
 ///
 /// [listeners]: ../../lightning/chain/trait.Listen.html
-pub struct ChainNotifier<'a, C: Cache, L: Deref> where L::Target: chain::Listen {
+pub struct ChainNotifier<'a, C: Cache, L: chain::Listen> {
 	/// Cache for looking up headers before fetching from a block source.
 	header_cache: &'a mut C,
 
@@ -298,7 +297,7 @@ struct ChainDifference {
 	connected_blocks: Vec<ValidatedBlockHeader>,
 }
 
-impl<'a, C: Cache, L: Deref> ChainNotifier<'a, C, L> where L::Target: chain::Listen {
+impl<'a, C: Cache, L: chain::Listen> ChainNotifier<'a, C, L> {
 	/// Finds the first common ancestor between `new_header` and `old_header`, disconnecting blocks
 	/// from `old_header` to get to that point and then connecting blocks until `new_header`.
 	///
@@ -420,7 +419,7 @@ mod spv_client_tests {
 		let poller = poll::ChainPoller::new(&mut chain, Network::Testnet);
 		let mut cache = UnboundedCache::new();
 		let mut listener = NullChainListener {};
-		let mut client = SpvClient::new(best_tip, poller, &mut cache, &mut listener);
+		let mut client = SpvClient::new(best_tip, poller, &mut cache, &listener);
 		match client.poll_best_tip().await {
 			Err(e) => {
 				assert_eq!(e.kind(), BlockSourceErrorKind::Persistent);
@@ -439,7 +438,7 @@ mod spv_client_tests {
 		let poller = poll::ChainPoller::new(&mut chain, Network::Testnet);
 		let mut cache = UnboundedCache::new();
 		let mut listener = NullChainListener {};
-		let mut client = SpvClient::new(common_tip, poller, &mut cache, &mut listener);
+		let mut client = SpvClient::new(common_tip, poller, &mut cache, &listener);
 		match client.poll_best_tip().await {
 			Err(e) => panic!("Unexpected error: {:?}", e),
 			Ok((chain_tip, blocks_connected)) => {
@@ -459,7 +458,7 @@ mod spv_client_tests {
 		let poller = poll::ChainPoller::new(&mut chain, Network::Testnet);
 		let mut cache = UnboundedCache::new();
 		let mut listener = NullChainListener {};
-		let mut client = SpvClient::new(old_tip, poller, &mut cache, &mut listener);
+		let mut client = SpvClient::new(old_tip, poller, &mut cache, &listener);
 		match client.poll_best_tip().await {
 			Err(e) => panic!("Unexpected error: {:?}", e),
 			Ok((chain_tip, blocks_connected)) => {
@@ -479,7 +478,7 @@ mod spv_client_tests {
 		let poller = poll::ChainPoller::new(&mut chain, Network::Testnet);
 		let mut cache = UnboundedCache::new();
 		let mut listener = NullChainListener {};
-		let mut client = SpvClient::new(old_tip, poller, &mut cache, &mut listener);
+		let mut client = SpvClient::new(old_tip, poller, &mut cache, &listener);
 		match client.poll_best_tip().await {
 			Err(e) => panic!("Unexpected error: {:?}", e),
 			Ok((chain_tip, blocks_connected)) => {
@@ -499,7 +498,7 @@ mod spv_client_tests {
 		let poller = poll::ChainPoller::new(&mut chain, Network::Testnet);
 		let mut cache = UnboundedCache::new();
 		let mut listener = NullChainListener {};
-		let mut client = SpvClient::new(old_tip, poller, &mut cache, &mut listener);
+		let mut client = SpvClient::new(old_tip, poller, &mut cache, &listener);
 		match client.poll_best_tip().await {
 			Err(e) => panic!("Unexpected error: {:?}", e),
 			Ok((chain_tip, blocks_connected)) => {
@@ -520,7 +519,7 @@ mod spv_client_tests {
 		let poller = poll::ChainPoller::new(&mut chain, Network::Testnet);
 		let mut cache = UnboundedCache::new();
 		let mut listener = NullChainListener {};
-		let mut client = SpvClient::new(best_tip, poller, &mut cache, &mut listener);
+		let mut client = SpvClient::new(best_tip, poller, &mut cache, &listener);
 		match client.poll_best_tip().await {
 			Err(e) => panic!("Unexpected error: {:?}", e),
 			Ok((chain_tip, blocks_connected)) => {

lightning/src/chain/mod.rs

@@ -137,6 +137,16 @@ pub trait Filter: Send + Sync {
 	fn register_output(&self, outpoint: &OutPoint, script_pubkey: &Script);
 }
 
+impl<T: Listen> Listen for &T {
+	fn block_connected(&self, block: &Block, height: u32) {
+		(**self).block_connected(block, height);
+	}
+
+	fn block_disconnected(&self, header: &BlockHeader, height: u32) {
+		(**self).block_disconnected(header, height);
+	}
+}
+
 impl<T: Listen> Listen for std::ops::Deref<Target = T> {
 	fn block_connected(&self, block: &Block, height: u32) {
 		(**self).block_connected(block, height);