Merge pull request #884 from TheBlueMatt/2021-04-bp-bindings

Prep background-processor for bindings inclusion

Author: TheBlueMatt

Cargo.toml

@@ -6,7 +6,7 @@ members = [
     "lightning-invoice",
     "lightning-net-tokio",
     "lightning-persister",
-    "background-processor",
+    "lightning-background-processor",
 ]
 
 # Our tests do actual crypo and lots of work, the tradeoff for -O1 is well worth it.

background-processor/Cargo.toml renamed to lightning-background-processor/Cargo.toml

@@ -20,6 +20,7 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::thread;
 use std::thread::JoinHandle;
 use std::time::{Duration, Instant};
+use std::ops::Deref;
 
 /// BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep
 /// Rust-Lightning running properly, and (2) either can or should be run in the background. Its
@@ -47,6 +48,38 @@ const FRESHNESS_TIMER: u64 = 60;
 #[cfg(test)]
 const FRESHNESS_TIMER: u64 = 1;
 
+/// Trait which handles persisting a [`ChannelManager`] to disk.
+///
+/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
+pub trait ChannelManagerPersister<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
+where
+	M::Target: 'static + chain::Watch<Signer>,
+	T::Target: 'static + BroadcasterInterface,
+	K::Target: 'static + KeysInterface<Signer = Signer>,
+	F::Target: 'static + FeeEstimator,
+	L::Target: 'static + Logger,
+{
+	/// Persist the given [`ChannelManager`] to disk, returning an error if persistence failed
+	/// (which will cause the [`BackgroundProcessor`] which called this method to exit.
+	///
+	/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
+	fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>;
+}
+
+impl<Fun, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
+ChannelManagerPersister<Signer, M, T, K, F, L> for Fun where
+	M::Target: 'static + chain::Watch<Signer>,
+	T::Target: 'static + BroadcasterInterface,
+	K::Target: 'static + KeysInterface<Signer = Signer>,
+	F::Target: 'static + FeeEstimator,
+	L::Target: 'static + Logger,
+	Fun: Fn(&ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error>,
+{
+	fn persist_manager(&self, channel_manager: &ChannelManager<Signer, M, T, K, F, L>) -> Result<(), std::io::Error> {
+		self(channel_manager)
+	}
+}
+
 impl BackgroundProcessor {
 	/// Start a background thread that takes care of responsibilities enumerated in the top-level
 	/// documentation.
@@ -66,25 +99,29 @@ impl BackgroundProcessor {
 	/// [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
 	/// [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
 	/// [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
-	pub fn start<PM, Signer, M, T, K, F, L, Descriptor: 'static + SocketDescriptor + Send, CM, RM>(
-		persist_channel_manager: PM,
-		channel_manager: Arc<ChannelManager<Signer, Arc<M>, Arc<T>, Arc<K>, Arc<F>, Arc<L>>>,
-		peer_manager: Arc<PeerManager<Descriptor, Arc<CM>, Arc<RM>, Arc<L>>>, logger: Arc<L>,
-	) -> Self
-	where
+	pub fn start<
 		Signer: 'static + Sign,
-		M: 'static + chain::Watch<Signer>,
-		T: 'static + BroadcasterInterface,
-		K: 'static + KeysInterface<Signer = Signer>,
-		F: 'static + FeeEstimator,
-		L: 'static + Logger,
-		CM: 'static + ChannelMessageHandler,
-		RM: 'static + RoutingMessageHandler,
-		PM: 'static
-			+ Send
-			+ Fn(
-				&ChannelManager<Signer, Arc<M>, Arc<T>, Arc<K>, Arc<F>, Arc<L>>,
-			) -> Result<(), std::io::Error>,
+		M: 'static + Deref + Send + Sync,
+		T: 'static + Deref + Send + Sync,
+		K: 'static + Deref + Send + Sync,
+		F: 'static + Deref + Send + Sync,
+		L: 'static + Deref + Send + Sync,
+		Descriptor: 'static + SocketDescriptor + Send + Sync,
+		CMH: 'static + Deref + Send + Sync,
+		RMH: 'static + Deref + Send + Sync,
+		CMP: 'static + Send + ChannelManagerPersister<Signer, M, T, K, F, L>,
+		CM: 'static + Deref<Target = ChannelManager<Signer, M, T, K, F, L>> + Send + Sync,
+		PM: 'static + Deref<Target = PeerManager<Descriptor, CMH, RMH, L>> + Send + Sync,
+	>
+	(handler: CMP, channel_manager: CM, peer_manager: PM, logger: L) -> Self
+	where
+		M::Target: 'static + chain::Watch<Signer>,
+		T::Target: 'static + BroadcasterInterface,
+		K::Target: 'static + KeysInterface<Signer = Signer>,
+		F::Target: 'static + FeeEstimator,
+		L::Target: 'static + Logger,
+		CMH::Target: 'static + ChannelMessageHandler,
+		RMH::Target: 'static + RoutingMessageHandler,
 	{
 		let stop_thread = Arc::new(AtomicBool::new(false));
 		let stop_thread_clone = stop_thread.clone();
@@ -95,7 +132,7 @@ impl BackgroundProcessor {
 				let updates_available =
 					channel_manager.await_persistable_update_timeout(Duration::from_millis(100));
 				if updates_available {
-					persist_channel_manager(&*channel_manager)?;
+					handler.persist_manager(&*channel_manager)?;
 				}
 				// Exit the loop if the background processor was requested to stop.
 				if stop_thread.load(Ordering::Acquire) == true {