Simplify implementation for KVStore trait objects

The implementation of the Persist and Persister trait for KVStore types
can also be used for trait objects if there is no implicit bound of
`Sized`.

Author: wvanlint

lightning/src/util/persist.rs

@@ -158,7 +158,7 @@ where
 }
 
 
-impl<'a, A: KVStore, CM: Deref, L: Deref, S: WriteableScore<'a>> Persister<'a, CM, L, S> for A
+impl<'a, A: KVStore + ?Sized, CM: Deref, L: Deref, S: WriteableScore<'a>> Persister<'a, CM, L, S> for A
 where
 	CM::Target: 'static + AChannelManager,
 	L::Target: 'static + Logger,
@@ -185,65 +185,7 @@ where
 	}
 }
 
-impl<'a, CM: Deref, L: Deref, S: WriteableScore<'a>> Persister<'a, CM, L, S> for dyn KVStore + Send + Sync
-where
-	CM::Target: 'static + AChannelManager,
-	L::Target: 'static + Logger,
-{
-	fn persist_manager(&self, channel_manager: &CM) -> Result<(), io::Error> {
-		self.write(CHANNEL_MANAGER_PERSISTENCE_PRIMARY_NAMESPACE,
-			CHANNEL_MANAGER_PERSISTENCE_SECONDARY_NAMESPACE,
-			CHANNEL_MANAGER_PERSISTENCE_KEY,
-			&channel_manager.get_cm().encode())
-	}
-
-	fn persist_graph(&self, network_graph: &NetworkGraph<L>) -> Result<(), io::Error> {
-		self.write(NETWORK_GRAPH_PERSISTENCE_PRIMARY_NAMESPACE,
-			NETWORK_GRAPH_PERSISTENCE_SECONDARY_NAMESPACE,
-			NETWORK_GRAPH_PERSISTENCE_KEY,
-			&network_graph.encode())
-	}
-
-	fn persist_scorer(&self, scorer: &S) -> Result<(), io::Error> {
-		self.write(SCORER_PERSISTENCE_PRIMARY_NAMESPACE,
-			SCORER_PERSISTENCE_SECONDARY_NAMESPACE,
-			SCORER_PERSISTENCE_KEY,
-			&scorer.encode())
-	}
-}
-
-impl<ChannelSigner: WriteableEcdsaChannelSigner, K: KVStore> Persist<ChannelSigner> for K {
-	// TODO: We really need a way for the persister to inform the user that its time to crash/shut
-	// down once these start returning failure.
-	// Then we should return InProgress rather than UnrecoverableError, implying we should probably
-	// just shut down the node since we're not retrying persistence!
-
-	fn persist_new_channel(&self, funding_txo: OutPoint, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
-		let key = format!("{}_{}", funding_txo.txid.to_string(), funding_txo.index);
-		match self.write(
-			CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
-			CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
-			&key, &monitor.encode())
-		{
-			Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
-			Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
-		}
-	}
-
-	fn update_persisted_channel(&self, funding_txo: OutPoint, _update: Option<&ChannelMonitorUpdate>, monitor: &ChannelMonitor<ChannelSigner>, _update_id: MonitorUpdateId) -> chain::ChannelMonitorUpdateStatus {
-		let key = format!("{}_{}", funding_txo.txid.to_string(), funding_txo.index);
-		match self.write(
-			CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE,
-			CHANNEL_MONITOR_PERSISTENCE_SECONDARY_NAMESPACE,
-			&key, &monitor.encode())
-		{
-			Ok(()) => chain::ChannelMonitorUpdateStatus::Completed,
-			Err(_) => chain::ChannelMonitorUpdateStatus::UnrecoverableError
-		}
-	}
-}
-
-impl<ChannelSigner: WriteableEcdsaChannelSigner> Persist<ChannelSigner> for dyn KVStore + Send + Sync {
+impl<ChannelSigner: WriteableEcdsaChannelSigner, K: KVStore + ?Sized> Persist<ChannelSigner> for K {
 	// TODO: We really need a way for the persister to inform the user that its time to crash/shut
 	// down once these start returning failure.
 	// Then we should return InProgress rather than UnrecoverableError, implying we should probably
@@ -901,6 +843,8 @@ mod tests {
 	use crate::ln::functional_test_utils::*;
 	use crate::util::test_utils::{self, TestLogger, TestStore};
 	use crate::{check_added_monitors, check_closed_broadcast};
+	use crate::sync::Arc;
+	use crate::util::test_channel_signer::TestChannelSigner;
 
 	const EXPECTED_UPDATES_PER_PAYMENT: u64 = 5;
 
@@ -1241,4 +1185,14 @@ mod tests {
 			.read(CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE, monitor_name.as_str(), UpdateName::from(u64::MAX - 1).as_str())
 			.is_err());
 	}
+
+	fn persist_fn<P: Deref, ChannelSigner: WriteableEcdsaChannelSigner>(_persist: P) -> bool where P::Target: Persist<ChannelSigner> {
+		true
+	}
+
+	#[test]
+	fn kvstore_trait_object_usage() {
+		let store: Arc<dyn KVStore + Send + Sync> = Arc::new(TestStore::new(false));
+		assert!(persist_fn::<_, TestChannelSigner>(store.clone()));
+	}
 }