X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchaininterface.rs;h=913fa007d378e91ba5666e3d34ae11c15010ce13;hb=620244dc2ec3153a61e009b80a8c59cf41514482;hp=2da2ae8c7eb618a49308e664e4a8edd50266bd58;hpb=b9707da1382bcebe066c0c26b15a975991bf81e2;p=rust-lightning

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index 2da2ae8c..913fa007 100644
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -13,476 +13,137 @@
 //! Includes traits for monitoring and receiving notifications of new blocks and block
 //! disconnections, transaction broadcasting, and feerate information requests.
 
-use bitcoin::blockdata::block::{Block, BlockHeader};
-use bitcoin::blockdata::transaction::Transaction;
-use bitcoin::blockdata::script::Script;
-use bitcoin::blockdata::constants::genesis_block;
-use bitcoin::network::constants::Network;
-use bitcoin::hash_types::{Txid, BlockHash};
+use core::{cmp, ops::Deref};
+use core::convert::TryInto;
 
-use std::sync::{Mutex, MutexGuard, Arc};
-use std::sync::atomic::{AtomicUsize, Ordering};
-use std::collections::HashSet;
-use std::ops::Deref;
-use std::marker::PhantomData;
-use std::ptr;
+use bitcoin::blockdata::transaction::Transaction;
 
-/// Used to give chain error details upstream
-#[derive(Clone)]
-pub enum ChainError {
-	/// Client doesn't support UTXO lookup (but the chain hash matches our genesis block hash)
-	NotSupported,
-	/// Chain isn't the one watched
-	NotWatched,
-	/// Tx doesn't exist or is unconfirmed
-	UnknownTx,
+// TODO: Define typed abstraction over feerates to handle their conversions.
+pub(crate) fn compute_feerate_sat_per_1000_weight(fee_sat: u64, weight: u64) -> u32 {
+	(fee_sat * 1000 / weight).try_into().unwrap_or(u32::max_value())
 }
-
-/// An interface to request notification of certain scripts as they appear the
-/// chain.
-///
-/// 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).
-pub trait ChainWatchInterface: Sync + Send {
-	/// Provides a txid/random-scriptPubKey-in-the-tx which much be watched for.
-	fn install_watch_tx(&self, txid: &Txid, script_pub_key: &Script);
-
-	/// Provides an outpoint which must be watched for, providing any transactions which spend the
-	/// given outpoint.
-	fn install_watch_outpoint(&self, outpoint: (Txid, u32), out_script: &Script);
-
-	/// Indicates that a listener needs to see all transactions.
-	fn watch_all_txn(&self);
-
-	/// Gets the script and value in satoshis for a given unspent transaction output given a
-	/// short_channel_id (aka unspent_tx_output_identier). For BTC/tBTC channels the top three
-	/// bytes are the block height, the next 3 the transaction index within the block, and the
-	/// final two the output within the transaction.
-	fn get_chain_utxo(&self, genesis_hash: BlockHash, unspent_tx_output_identifier: u64) -> Result<(Script, u64), ChainError>;
-
-	/// Gets the list of transaction indices within a given block that the ChainWatchInterface is
-	/// watching for.
-	fn filter_block(&self, block: &Block) -> Vec<usize>;
-
-	/// Returns a usize that changes when the ChainWatchInterface's watched data is modified.
-	/// Users of `filter_block` should pre-save a copy of `reentered`'s return value and use it to
-	/// determine whether they need to re-filter a given block.
-	fn reentered(&self) -> usize;
+pub(crate) const fn fee_for_weight(feerate_sat_per_1000_weight: u32, weight: u64) -> u64 {
+	((feerate_sat_per_1000_weight as u64 * weight) + 1000 - 1) / 1000
 }
 
 /// An interface to send a transaction to the Bitcoin network.
-pub trait BroadcasterInterface: Sync + Send {
-	/// Sends a transaction out to (hopefully) be mined.
-	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.
-	///
-	/// The txn_matched array should be set to references to transactions which matched the
-	/// relevant installed watch outpoints/txn, or the full set of transactions in the block.
+pub trait BroadcasterInterface {
+	/// Sends a list of transactions out to (hopefully) be mined.
+	/// This only needs to handle the actual broadcasting of transactions, LDK will automatically
+	/// rebroadcast transactions that haven't made it into a block.
 	///
-	/// Note that if txn_matched includes only matched transactions, and a new
-	/// transaction/outpoint is watched during a block_connected call, the block *must* be
-	/// re-scanned with the new transaction/outpoints and block_connected should be called
-	/// again with the same header and (at least) the new transactions.
+	/// In some cases LDK may attempt to broadcast a transaction which double-spends another
+	/// and this isn't a bug and can be safely ignored.
 	///
-	/// Note that if non-new transaction/outpoints are be registered during a call, a second call
-	/// *must not* happen.
+	/// If more than one transaction is given, these transactions should be considered to be a
+	/// package and broadcast together. Some of the transactions may or may not depend on each other,
+	/// be sure to manage both cases correctly.
 	///
-	/// This also means those counting confirmations using block_connected callbacks should watch
-	/// for duplicate headers and not count them towards confirmations!
-	fn block_connected(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[usize]);
-	/// 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);
+	/// Bitcoin transaction packages are defined in BIP 331 and here:
+	/// https://github.com/bitcoin/bitcoin/blob/master/doc/policy/packages.md
+	fn broadcast_transactions(&self, txs: &[&Transaction]);
 }
 
-/// An enum that represents the speed at which we want a transaction to confirm used for feerate
+/// An enum that represents the priority at which we want a transaction to confirm used for feerate
 /// estimation.
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub enum ConfirmationTarget {
-	/// We are happy with this transaction confirming slowly when feerate drops some.
+	/// We'd like a transaction to confirm in the future, but don't want to commit most of the fees
+	/// required to do so yet. The remaining fees will come via a Child-Pays-For-Parent (CPFP) fee
+	/// bump of the transaction.
+	///
+	/// The feerate returned should be the absolute minimum feerate required to enter most node
+	/// mempools across the network. Note that if you are not able to obtain this feerate estimate,
+	/// you should likely use the furthest-out estimate allowed by your fee estimator.
+	MempoolMinimum,
+	/// We are happy with a transaction confirming slowly, at least within a day or so worth of
+	/// blocks.
 	Background,
-	/// We'd like this transaction to confirm without major delay, but 12-18 blocks is fine.
+	/// We'd like a transaction to confirm without major delayed, i.e., within the next 12-24 blocks.
 	Normal,
-	/// We'd like this transaction to confirm in the next few blocks.
+	/// We'd like a transaction to confirm in the next few blocks.
 	HighPriority,
 }
 
 /// A trait which should be implemented to provide feerate information on a number of time
 /// horizons.
 ///
+/// If access to a local mempool is not feasible, feerate estimates should be fetched from a set of
+/// third-parties hosting them. Note that this enables them to affect the propagation of your
+/// pre-signed transactions at any time and therefore endangers the safety of channels funds. It
+/// should be considered carefully as a deployment.
+///
 /// 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).
-pub trait FeeEstimator: Sync + Send {
+/// called from inside the library in response to chain events, P2P events, or timer events).
+pub trait FeeEstimator {
 	/// Gets estimated satoshis of fee required per 1000 Weight-Units.
 	///
-	/// Must be no smaller than 253 (ie 1 satoshi-per-byte rounded up to ensure later round-downs
-	/// don't put us below 1 satoshi-per-byte).
+	/// LDK will wrap this method and ensure that the value returned is no smaller than 253
+	/// (ie 1 satoshi-per-byte rounded up to ensure later round-downs don't put us below 1 satoshi-per-byte).
 	///
-	/// This translates to:
+	/// The following unit conversions can be used to convert to sats/KW:
 	///  * satoshis-per-byte * 250
-	///  * ceil(satoshis-per-kbyte / 4)
+	///  * satoshis-per-kbyte / 4
 	fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32;
 }
 
 /// Minimum relay fee as required by bitcoin network mempool policy.
 pub const MIN_RELAY_FEE_SAT_PER_1000_WEIGHT: u64 = 4000;
+/// Minimum feerate that takes a sane approach to bitcoind weight-to-vbytes rounding.
+/// See the following Core Lightning commit for an explanation:
+/// <https://github.com/ElementsProject/lightning/commit/2e687b9b352c9092b5e8bd4a688916ac50b44af0>
+pub const FEERATE_FLOOR_SATS_PER_KW: u32 = 253;
 
-/// Utility for tracking registered txn/outpoints and checking for matches
-#[cfg_attr(test, derive(PartialEq))]
-pub struct ChainWatchedUtil {
-	watch_all: bool,
-
-	// We are more conservative in matching during testing to ensure everything matches *exactly*,
-	// even though during normal runtime we take more optimized match approaches...
-	#[cfg(test)]
-	watched_txn: HashSet<(Txid, Script)>,
-	#[cfg(not(test))]
-	watched_txn: HashSet<Script>,
-
-	watched_outpoints: HashSet<(Txid, u32)>,
-}
-
-impl ChainWatchedUtil {
-	/// Constructs an empty (watches nothing) ChainWatchedUtil
-	pub fn new() -> Self {
-		Self {
-			watch_all: false,
-			watched_txn: HashSet::new(),
-			watched_outpoints: HashSet::new(),
-		}
-	}
-
-	/// Registers a tx for monitoring, returning true if it was a new tx and false if we'd already
-	/// been watching for it.
-	pub fn register_tx(&mut self, txid: &Txid, script_pub_key: &Script) -> bool {
-		if self.watch_all { return false; }
-		#[cfg(test)]
-		{
-			self.watched_txn.insert((txid.clone(), script_pub_key.clone()))
-		}
-		#[cfg(not(test))]
-		{
-			let _tx_unused = txid; // It's used in cfg(test), though
-			self.watched_txn.insert(script_pub_key.clone())
-		}
-	}
-
-	/// Registers an outpoint for monitoring, returning true if it was a new outpoint and false if
-	/// we'd already been watching for it
-	pub fn register_outpoint(&mut self, outpoint: (Txid, u32), _script_pub_key: &Script) -> bool {
-		if self.watch_all { return false; }
-		self.watched_outpoints.insert(outpoint)
-	}
-
-	/// Sets us to match all transactions, returning true if this is a new setting and false if
-	/// we'd already been set to match everything.
-	pub fn watch_all(&mut self) -> bool {
-		if self.watch_all { return false; }
-		self.watch_all = true;
-		true
-	}
-
-	/// Checks if a given transaction matches the current filter.
-	pub fn does_match_tx(&self, tx: &Transaction) -> bool {
-		if self.watch_all {
-			return true;
-		}
-		for out in tx.output.iter() {
-			#[cfg(test)]
-			for &(ref txid, ref script) in self.watched_txn.iter() {
-				if *script == out.script_pubkey {
-					if tx.txid() == *txid {
-						return true;
-					}
-				}
-			}
-			#[cfg(not(test))]
-			for script in self.watched_txn.iter() {
-				if *script == out.script_pubkey {
-					return true;
-				}
-			}
-		}
-		for input in tx.input.iter() {
-			for outpoint in self.watched_outpoints.iter() {
-				let &(outpoint_hash, outpoint_index) = outpoint;
-				if outpoint_hash == input.previous_output.txid && outpoint_index == input.previous_output.vout {
-					return true;
-				}
-			}
-		}
-		false
-	}
-}
-
-/// BlockNotifierArc is useful when you need a BlockNotifier that points to ChainListeners with
-/// static lifetimes, e.g. when you're using lightning-net-tokio (since tokio::spawn requires
-/// parameters with static lifetimes). Other times you can afford a reference, which is more
-/// efficient, in which case BlockNotifierRef is a more appropriate type. Defining these type
-/// aliases prevents issues such as overly long function definitions.
-pub type BlockNotifierArc<C> = Arc<BlockNotifier<'static, Arc<ChainListener>, C>>;
-
-/// BlockNotifierRef is useful when you want a BlockNotifier that points to ChainListeners
-/// with nonstatic lifetimes. This is useful for when static lifetimes are not needed. Nonstatic
-/// lifetimes are more efficient but less flexible, and should be used by default unless static
-/// lifetimes are required, e.g. when you're using lightning-net-tokio (since tokio::spawn
-/// requires parameters with static lifetimes), in which case BlockNotifierArc is a more
-/// appropriate type. Defining these type aliases for common usages prevents issues such as
-/// overly long function definitions.
-pub type BlockNotifierRef<'a, C> = BlockNotifier<'a, &'a ChainListener, C>;
-
-/// Utility for notifying listeners about new blocks, and handling block rescans if new watch
-/// data is registered.
+/// Wraps a `Deref` to a `FeeEstimator` so that any fee estimations provided by it
+/// are bounded below by `FEERATE_FLOOR_SATS_PER_KW` (253 sats/KW).
 ///
-/// Rather than using a plain BlockNotifier, it is preferable to use either a BlockNotifierArc
-/// or a BlockNotifierRef for conciseness. See their documentation for more details, but essentially
-/// you should default to using a BlockNotifierRef, and use a BlockNotifierArc instead when you
-/// require ChainListeners with static lifetimes, such as when you're using lightning-net-tokio.
-pub struct BlockNotifier<'a, CL: Deref + 'a, C: Deref>
-		where CL::Target: ChainListener + 'a, C::Target: ChainWatchInterface {
-	listeners: Mutex<Vec<CL>>,
-	chain_monitor: C,
-	phantom: PhantomData<&'a ()>,
-}
-
-impl<'a, CL: Deref + 'a, C: Deref> BlockNotifier<'a, CL, C>
-		where CL::Target: ChainListener + 'a, C::Target: ChainWatchInterface {
-	/// Constructs a new BlockNotifier without any listeners.
-	pub fn new(chain_monitor: C) -> BlockNotifier<'a, CL, C> {
-		BlockNotifier {
-			listeners: Mutex::new(Vec::new()),
-			chain_monitor,
-			phantom: PhantomData,
-		}
-	}
-
-	/// Register the given listener to receive events.
-	pub fn register_listener(&self, listener: CL) {
-		let mut vec = self.listeners.lock().unwrap();
-		vec.push(listener);
-	}
-	/// Unregister the given listener to no longer
-	/// receive events.
-	///
-	/// If the same listener is registered multiple times, unregistering
-	/// will remove ALL occurrences of that listener. Comparison is done using
-	/// the pointer returned by the Deref trait implementation.
-	pub fn unregister_listener(&self, listener: CL) {
-		let mut vec = self.listeners.lock().unwrap();
-		// item is a ref to an abstract thing that dereferences to a ChainListener,
-		// so dereference it twice to get the ChainListener itself
-		vec.retain(|item | !ptr::eq(&(**item), &(*listener)));
-	}
+/// Note that this does *not* implement [`FeeEstimator`] to make it harder to accidentally mix the
+/// two.
+pub(crate) struct LowerBoundedFeeEstimator<F: Deref>(pub F) where F::Target: FeeEstimator;
 
-	/// Notify listeners that a block was connected given a full, unfiltered block.
-	///
-	/// Handles re-scanning the block and calling block_connected again if listeners register new
-	/// watch data during the callbacks for you (see ChainListener::block_connected for more info).
-	pub fn block_connected(&self, block: &Block, height: u32) {
-		let mut reentered = true;
-		while reentered {
-			let matched_indexes = self.chain_monitor.filter_block(block);
-			let mut matched_txn = Vec::new();
-			for index in matched_indexes.iter() {
-				matched_txn.push(&block.txdata[*index]);
-			}
-			reentered = self.block_connected_checked(&block.header, height, matched_txn.as_slice(), matched_indexes.as_slice());
-		}
+impl<F: Deref> LowerBoundedFeeEstimator<F> where F::Target: FeeEstimator {
+	/// Creates a new `LowerBoundedFeeEstimator` which wraps the provided fee_estimator
+	pub fn new(fee_estimator: F) -> Self {
+		LowerBoundedFeeEstimator(fee_estimator)
 	}
 
-	/// Notify listeners that a block was connected, given pre-filtered list of transactions in the
-	/// block which matched the filter (probably using does_match_tx).
-	///
-	/// Returns true if notified listeners registered additional watch data (implying that the
-	/// block must be re-scanned and this function called again prior to further block_connected
-	/// calls, see ChainListener::block_connected for more info).
-	pub fn block_connected_checked(&self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[usize]) -> bool {
-		let last_seen = self.chain_monitor.reentered();
-
-		let listeners = self.listeners.lock().unwrap();
-		for listener in listeners.iter() {
-			listener.block_connected(header, height, txn_matched, indexes_of_txn_matched);
-		}
-		return last_seen != self.chain_monitor.reentered();
+	pub fn bounded_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32 {
+		cmp::max(
+			self.0.get_est_sat_per_1000_weight(confirmation_target),
+			FEERATE_FLOOR_SATS_PER_KW,
+		)
 	}
-
-	/// Notify listeners that a block was disconnected.
-	pub fn block_disconnected(&self, header: &BlockHeader, disconnected_height: u32) {
-		let listeners = self.listeners.lock().unwrap();
-		for listener in listeners.iter() {
-			listener.block_disconnected(&header, disconnected_height);
-		}
-	}
-}
-
-/// Utility to capture some common parts of ChainWatchInterface implementors.
-///
-/// Keeping a local copy of this in a ChainWatchInterface implementor is likely useful.
-pub struct ChainWatchInterfaceUtil {
-	network: Network,
-	watched: Mutex<ChainWatchedUtil>,
-	reentered: AtomicUsize,
 }
 
-// We only expose PartialEq in test since its somewhat unclear exactly what it should do and we're
-// only comparing a subset of fields (essentially just checking that the set of things we're
-// watching is the same).
 #[cfg(test)]
-impl PartialEq for ChainWatchInterfaceUtil {
-	fn eq(&self, o: &Self) -> bool {
-		self.network == o.network &&
-		*self.watched.lock().unwrap() == *o.watched.lock().unwrap()
-	}
-}
-
-/// Register listener
-impl ChainWatchInterface for ChainWatchInterfaceUtil {
-	fn install_watch_tx(&self, txid: &Txid, script_pub_key: &Script) {
-		let mut watched = self.watched.lock().unwrap();
-		if watched.register_tx(txid, script_pub_key) {
-			self.reentered.fetch_add(1, Ordering::Relaxed);
-		}
-	}
-
-	fn install_watch_outpoint(&self, outpoint: (Txid, u32), out_script: &Script) {
-		let mut watched = self.watched.lock().unwrap();
-		if watched.register_outpoint(outpoint, out_script) {
-			self.reentered.fetch_add(1, Ordering::Relaxed);
-		}
-	}
-
-	fn watch_all_txn(&self) {
-		let mut watched = self.watched.lock().unwrap();
-		if watched.watch_all() {
-			self.reentered.fetch_add(1, Ordering::Relaxed);
-		}
-	}
-
-	fn get_chain_utxo(&self, genesis_hash: BlockHash, _unspent_tx_output_identifier: u64) -> Result<(Script, u64), ChainError> {
-		if genesis_hash != genesis_block(self.network).header.block_hash() {
-			return Err(ChainError::NotWatched);
-		}
-		Err(ChainError::NotSupported)
-	}
-
-	fn filter_block(&self, block: &Block) -> Vec<usize> {
-		let mut matched_index = Vec::new();
-		{
-			let watched = self.watched.lock().unwrap();
-			for (index, transaction) in block.txdata.iter().enumerate() {
-				if self.does_match_tx_unguarded(transaction, &watched) {
-					matched_index.push(index);
-				}
-			}
-		}
-		matched_index
-	}
+mod tests {
+	use super::{FEERATE_FLOOR_SATS_PER_KW, LowerBoundedFeeEstimator, ConfirmationTarget, FeeEstimator};
 
-	fn reentered(&self) -> usize {
-		self.reentered.load(Ordering::Relaxed)
+	struct TestFeeEstimator {
+		sat_per_kw: u32,
 	}
-}
 
-impl ChainWatchInterfaceUtil {
-	/// Creates a new ChainWatchInterfaceUtil for the given network
-	pub fn new(network: Network) -> ChainWatchInterfaceUtil {
-		ChainWatchInterfaceUtil {
-			network,
-			watched: Mutex::new(ChainWatchedUtil::new()),
-			reentered: AtomicUsize::new(1),
+	impl FeeEstimator for TestFeeEstimator {
+		fn get_est_sat_per_1000_weight(&self, _: ConfirmationTarget) -> u32 {
+			self.sat_per_kw
 		}
 	}
 
-	/// Checks if a given transaction matches the current filter.
-	pub fn does_match_tx(&self, tx: &Transaction) -> bool {
-		let watched = self.watched.lock().unwrap();
-		self.does_match_tx_unguarded (tx, &watched)
-	}
-
-	fn does_match_tx_unguarded(&self, tx: &Transaction, watched: &MutexGuard<ChainWatchedUtil>) -> bool {
-		watched.does_match_tx(tx)
-	}
-}
-
-#[cfg(test)]
-mod tests {
-	use ln::functional_test_utils::{create_chanmon_cfgs, create_node_cfgs};
-	use super::{BlockNotifier, ChainListener};
-	use std::ptr;
-
 	#[test]
-	fn register_listener_test() {
-		let chanmon_cfgs = create_chanmon_cfgs(1);
-		let node_cfgs = create_node_cfgs(1, &chanmon_cfgs);
-		let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor);
-		assert_eq!(block_notifier.listeners.lock().unwrap().len(), 0);
-		let listener = &node_cfgs[0].chan_monitor.simple_monitor as &ChainListener;
-		block_notifier.register_listener(listener);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 1);
-		let item = vec.first().clone().unwrap();
-		assert!(ptr::eq(&(**item), &(*listener)));
-	}
+	fn test_fee_estimator_less_than_floor() {
+		let sat_per_kw = FEERATE_FLOOR_SATS_PER_KW - 1;
+		let test_fee_estimator = &TestFeeEstimator { sat_per_kw };
+		let fee_estimator = LowerBoundedFeeEstimator::new(test_fee_estimator);
 
-	#[test]
-	fn unregister_single_listener_test() {
-		let chanmon_cfgs = create_chanmon_cfgs(2);
-		let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
-		let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor);
-		let listener1 = &node_cfgs[0].chan_monitor.simple_monitor as &ChainListener;
-		let listener2 = &node_cfgs[1].chan_monitor.simple_monitor as &ChainListener;
-		block_notifier.register_listener(listener1);
-		block_notifier.register_listener(listener2);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 2);
-		drop(vec);
-		block_notifier.unregister_listener(listener1);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 1);
-		let item = vec.first().clone().unwrap();
-		assert!(ptr::eq(&(**item), &(*listener2)));
+		assert_eq!(fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background), FEERATE_FLOOR_SATS_PER_KW);
 	}
 
 	#[test]
-	fn unregister_single_listener_ref_test() {
-		let chanmon_cfgs = create_chanmon_cfgs(2);
-		let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
-		let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor);
-		block_notifier.register_listener(&node_cfgs[0].chan_monitor.simple_monitor as &ChainListener);
-		block_notifier.register_listener(&node_cfgs[1].chan_monitor.simple_monitor as &ChainListener);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 2);
-		drop(vec);
-		block_notifier.unregister_listener(&node_cfgs[0].chan_monitor.simple_monitor);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 1);
-		let item = vec.first().clone().unwrap();
-		assert!(ptr::eq(&(**item), &(*&node_cfgs[1].chan_monitor.simple_monitor)));
-	}
+	fn test_fee_estimator_greater_than_floor() {
+		let sat_per_kw = FEERATE_FLOOR_SATS_PER_KW + 1;
+		let test_fee_estimator = &TestFeeEstimator { sat_per_kw };
+		let fee_estimator = LowerBoundedFeeEstimator::new(test_fee_estimator);
 
-	#[test]
-	fn unregister_multiple_of_the_same_listeners_test() {
-		let chanmon_cfgs = create_chanmon_cfgs(2);
-		let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
-		let block_notifier = BlockNotifier::new(node_cfgs[0].chain_monitor);
-		let listener1 = &node_cfgs[0].chan_monitor.simple_monitor as &ChainListener;
-		let listener2 = &node_cfgs[1].chan_monitor.simple_monitor as &ChainListener;
-		block_notifier.register_listener(listener1);
-		block_notifier.register_listener(listener1);
-		block_notifier.register_listener(listener2);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 3);
-		drop(vec);
-		block_notifier.unregister_listener(listener1);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 1);
-		let item = vec.first().clone().unwrap();
-		assert!(ptr::eq(&(**item), &(*listener2)));
+		assert_eq!(fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background), sat_per_kw);
 	}
 }