X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchaininterface.rs;h=e923a94bb6d3e7afb5f37376b6de132225821d21;hb=da34ada8d4df31f96e69133e7bdad891a2710001;hp=aa69d8596f63efd15c09011fc50c5af8795c74a2;hpb=bc4f4631ccda9045a0f3ec884109de49f3a0db12;p=rust-lightning

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index aa69d859..e923a94b 100644
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -13,37 +13,19 @@
 //! 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::hash_types::Txid;
+use core::{cmp, ops::Deref};
 
-use std::sync::{Mutex, Arc};
-use std::collections::HashSet;
-use std::ops::Deref;
-use std::marker::PhantomData;
-use std::ptr;
+use bitcoin::blockdata::transaction::Transaction;
 
 /// An interface to send a transaction to the Bitcoin network.
-pub trait BroadcasterInterface: Sync + Send {
+pub trait BroadcasterInterface {
 	/// 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. 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.
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub enum ConfirmationTarget {
 	/// We are happy with this transaction confirming slowly when feerate drops some.
 	Background,
@@ -57,247 +39,76 @@ 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).
-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.
-///
-/// (C-not exported) as we let clients handle any reference counting they need to do
-pub type BlockNotifierArc = Arc<BlockNotifier<'static, Arc<ChainListener>>>;
-
-/// 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> = BlockNotifier<'a, &'a ChainListener>;
-
-/// Utility for notifying listeners when blocks are connected or disconnected.
+/// 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>
-		where CL::Target: ChainListener + 'a {
-	listeners: Mutex<Vec<CL>>,
-	phantom: PhantomData<&'a ()>,
-}
-
-impl<'a, CL: Deref + 'a> BlockNotifier<'a, CL>
-		where CL::Target: ChainListener + 'a {
-	/// Constructs a new BlockNotifier without any listeners.
-	pub fn new() -> BlockNotifier<'a, CL> {
-		BlockNotifier {
-			listeners: Mutex::new(Vec::new()),
-			phantom: PhantomData,
-		}
+/// 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;
+
+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)
 	}
 
-	/// 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.
-	///
-	/// (C-not exported) because the equality check would always fail
-	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)));
-	}
-
-	/// Notify listeners that a block was connected.
-	pub fn block_connected(&self, block: &Block, height: u32) {
-		let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
-		let listeners = self.listeners.lock().unwrap();
-		for listener in listeners.iter() {
-			listener.block_connected(&block.header, &txdata, height);
-		}
-	}
-
-	/// 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);
-		}
+	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,
+		)
 	}
 }
 
 #[cfg(test)]
 mod tests {
-	use bitcoin::blockdata::block::BlockHeader;
-	use bitcoin::blockdata::transaction::Transaction;
-	use super::{BlockNotifier, ChainListener};
-	use std::ptr;
+	use super::{FEERATE_FLOOR_SATS_PER_KW, LowerBoundedFeeEstimator, ConfirmationTarget, FeeEstimator};
 
-	struct TestChainListener(u8);
-
-	impl ChainListener for TestChainListener {
-		fn block_connected(&self, _header: &BlockHeader, _txdata: &[(usize, &Transaction)], _height: u32) {}
-		fn block_disconnected(&self, _header: &BlockHeader, _disconnected_height: u32) {}
+	struct TestFeeEstimator {
+		sat_per_kw: u32,
 	}
 
-	#[test]
-	fn register_listener_test() {
-		let block_notifier = BlockNotifier::new();
-		assert_eq!(block_notifier.listeners.lock().unwrap().len(), 0);
-		let listener = &TestChainListener(0);
-		block_notifier.register_listener(listener as &ChainListener);
-		let vec = block_notifier.listeners.lock().unwrap();
-		assert_eq!(vec.len(), 1);
-		let item = vec.first().unwrap();
-		assert!(ptr::eq(&(**item), listener));
+	impl FeeEstimator for TestFeeEstimator {
+		fn get_est_sat_per_1000_weight(&self, _: ConfirmationTarget) -> u32 {
+			self.sat_per_kw
+		}
 	}
 
 	#[test]
-	fn unregister_single_listener_test() {
-		let block_notifier = BlockNotifier::new();
-		let listener1 = &TestChainListener(1);
-		let listener2 = &TestChainListener(2);
-		block_notifier.register_listener(listener1 as &ChainListener);
-		block_notifier.register_listener(listener2 as &ChainListener);
-		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().unwrap();
-		assert!(ptr::eq(&(**item), listener2));
+	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);
+
+		assert_eq!(fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background), FEERATE_FLOOR_SATS_PER_KW);
 	}
 
 	#[test]
-	fn unregister_multiple_of_the_same_listeners_test() {
-		let block_notifier = BlockNotifier::new();
-		let listener1 = &TestChainListener(1);
-		let listener2 = &TestChainListener(2);
-		block_notifier.register_listener(listener1 as &ChainListener);
-		block_notifier.register_listener(listener1 as &ChainListener);
-		block_notifier.register_listener(listener2 as &ChainListener);
-		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().unwrap();
-		assert!(ptr::eq(&(**item), listener2));
+	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);
+
+		assert_eq!(fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background), sat_per_kw);
 	}
 }