Remove ChainListener

BlockNotifier was removed in the previous commit, thus ChainListener is
no longer needed. Instead, anything needing chain events should be
notified directly.

Author: jkczyz

fuzz/src/chanmon_consistency.rs

@@ -22,7 +22,7 @@ use bitcoin::hash_types::{BlockHash, WPubkeyHash};
 
 use lightning::chain;
 use lightning::chain::transaction::OutPoint;
-use lightning::chain::chaininterface::{BroadcasterInterface, ChainListener, ConfirmationTarget, FeeEstimator};
+use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
 use lightning::chain::keysinterface::{KeysInterface, InMemoryChannelKeys};
 use lightning::ln::channelmonitor;
 use lightning::ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, HTLCUpdate};

fuzz/src/full_stack.rs

@@ -18,7 +18,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
 
 use lightning::chain;
-use lightning::chain::chaininterface::{BroadcasterInterface,ConfirmationTarget,ChainListener,FeeEstimator};
+use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::keysinterface::{InMemoryChannelKeys, KeysInterface};
 use lightning::ln::channelmonitor;

lightning/src/chain/chaininterface.rs

@@ -4,7 +4,6 @@
 //! Includes traits for monitoring and receiving notifications of new blocks and block
 //! disconnections, transaction broadcasting, and feerate information requests.
 
-use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::blockdata::transaction::Transaction;
 use bitcoin::blockdata::script::Script;
 use bitcoin::hash_types::Txid;
@@ -17,18 +16,6 @@ pub trait BroadcasterInterface: Sync + Send {
 	fn broadcast_transaction(&self, tx: &Transaction);
 }
 
-/// A trait indicating a desire to listen for events from the chain
-pub trait ChainListener: Sync + Send {
-	/// Notifies a listener that a block was connected. Transactions may be filtered and are given
-	/// paired with their position within the block.
-	fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32);
-
-	/// Notifies a listener that a block was disconnected.
-	/// Unlike block_connected, this *must* never be called twice for the same disconnect event.
-	/// Height must be the one of the block which was disconnected (not new height of the best chain)
-	fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32);
-}
-
 /// An enum that represents the speed at which we want a transaction to confirm used for feerate
 /// estimation.
 pub enum ConfirmationTarget {
@@ -44,8 +31,7 @@ pub enum ConfirmationTarget {
 /// horizons.
 ///
 /// Note that all of the functions implemented here *must* be reentrant-safe (obviously - they're
-/// called from inside the library in response to ChainListener events, P2P events, or timer
-/// events).
+/// called from inside the library in response to chain events, P2P events, or timer events).
 pub trait FeeEstimator: Sync + Send {
 	/// Gets estimated satoshis of fee required per 1000 Weight-Units.
 	///

lightning/src/ln/channelmanager.rs

@@ -28,7 +28,7 @@ use bitcoin::secp256k1;
 
 use chain;
 use chain::Watch;
-use chain::chaininterface::{BroadcasterInterface,ChainListener,FeeEstimator};
+use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::transaction::OutPoint;
 use ln::channel::{Channel, ChannelError};
 use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, HTLC_FAIL_BACK_BUFFER, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY};
@@ -2968,15 +2968,15 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
 	}
 }
 
-impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send, T: Deref + Sync + Send, K: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send>
-	ChainListener for ChannelManager<ChanSigner, M, T, K, F, L>
+impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<ChanSigner, M, T, K, F, L>
 	where M::Target: chain::Watch<Keys=ChanSigner>,
         T::Target: BroadcasterInterface,
         K::Target: KeysInterface<ChanKeySigner = ChanSigner>,
         F::Target: FeeEstimator,
-				L::Target: Logger,
+        L::Target: Logger,
 {
-	fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32) {
+	///
+	pub fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32) {
 		let header_hash = header.bitcoin_hash();
 		log_trace!(self.logger, "Block {} at height {} connected", header_hash, height);
 		let _ = self.total_consistency_lock.read().unwrap();
@@ -3103,7 +3103,7 @@ impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send, T: Deref + Sync + Send, K:
 	}
 
 	/// We force-close the channel without letting our counterparty participate in the shutdown
-	fn block_disconnected(&self, header: &BlockHeader, _: u32) {
+	pub fn block_disconnected(&self, header: &BlockHeader, _: u32) {
 		let _ = self.total_consistency_lock.read().unwrap();
 		let mut failed_channels = Vec::new();
 		{

lightning/src/ln/channelmonitor.rs

@@ -35,7 +35,7 @@ use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, Loca
 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
 use chain;
-use chain::chaininterface::{ChainListener, ChainWatchedUtil, BroadcasterInterface, FeeEstimator};
+use chain::chaininterface::{ChainWatchedUtil, BroadcasterInterface, FeeEstimator};
 use chain::transaction::OutPoint;
 use chain::keysinterface::{SpendableOutputDescriptor, ChannelKeys};
 use util::logger::Logger;
@@ -154,7 +154,7 @@ pub struct HTLCUpdate {
 }
 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
 
-/// An implementation of a [`chain::Watch`] and ChainListener.
+/// An implementation of [`chain::Watch`].
 ///
 /// May be used in conjunction with [`ChannelManager`] to monitor channels locally or used
 /// independently to monitor channels remotely.
@@ -218,13 +218,17 @@ impl WatchEventQueue {
 	}
 }
 
-impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send>
-	ChainListener for ChainMonitor<ChanSigner, T, F, L>
+impl<ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> ChainMonitor<Key, ChanSigner, T, F, L>
 	where T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
 {
-	fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32) {
+	/// Delegates to [`ChannelMonitor::block_connected`] for each watched channel. Any HTLCs that
+	/// were resolved on chain will be retuned by [`chain::Watch::release_pending_htlc_updates`].
+	///
+	/// [`ChannelMonitor::block_connected`]: struct.ChannelMonitor.html#method.block_connected
+	/// [`chain::Watch::release_pending_htlc_updates`]: ../../chain/trait.Watch.html#tymethod.release_pending_htlc_updates
+	pub fn block_connected(&self, header: &BlockHeader, txdata: &[(usize, &Transaction)], height: u32) {
 		let mut watch_events = self.watch_events.lock().unwrap();
 		let matched_txn: Vec<_> = txdata.iter().filter(|&&(_, tx)| watch_events.watched.does_match_tx(tx)).map(|e| *e).collect();
 		{
@@ -241,7 +245,10 @@ impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L:
 		}
 	}
 
-	fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
+	/// Delegates to [`ChannelMonitor::block_disconnected`] for each watched channel.
+	///
+	/// [`ChannelMonitor::block_disconnected`]: struct.ChannelMonitor.html#method.block_disconnected
+	pub fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
 		let mut monitors = self.monitors.lock().unwrap();
 		for monitor in monitors.values_mut() {
 			monitor.block_disconnected(header, disconnected_height, &*self.broadcaster, &*self.fee_estimator, &*self.logger);

lightning/src/ln/functional_test_utils.rs

@@ -3,7 +3,6 @@
 
 use chain;
 use chain::Watch;
-use chain::chaininterface::ChainListener;
 use chain::transaction::OutPoint;
 use ln::channelmanager::{ChannelManager, ChannelManagerReadArgs, RAACommitmentOrder, PaymentPreimage, PaymentHash, PaymentSecret, PaymentSendFailure};
 use ln::channelmonitor::ChannelMonitor;

lightning/src/ln/functional_tests.rs

@@ -5,7 +5,6 @@
 use chain::Watch;
 use chain::transaction::OutPoint;
 use chain::keysinterface::{ChannelKeys, KeysInterface, SpendableOutputDescriptor};
-use chain::chaininterface::ChainListener;
 use ln::channel::{COMMITMENT_TX_BASE_WEIGHT, COMMITMENT_TX_WEIGHT_PER_HTLC};
 use ln::channelmanager::{ChannelManager,ChannelManagerReadArgs,HTLCForwardInfo,RAACommitmentOrder, PaymentPreimage, PaymentHash, PaymentSecret, PaymentSendFailure, BREAKDOWN_TIMEOUT};
 use ln::channelmonitor::{ChannelMonitor, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY};