X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fchaininterface.rs;h=4204d714f1b12be5a7a1a04fed5092746562c827;hb=db3d58c586b9f2972414a07b09980db710428c7a;hp=a63e0bf1069475f4362ae69c17265519fadc8381;hpb=1599a13643d893277eb3921c1bb15297547eb030;p=rust-lightning

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index a63e0bf1..4204d714 100644
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -13,26 +13,46 @@
 //! Includes traits for monitoring and receiving notifications of new blocks and block
 //! disconnections, transaction broadcasting, and feerate information requests.
 
-use bitcoin::blockdata::transaction::Transaction;
-use bitcoin::blockdata::script::Script;
-use bitcoin::hash_types::Txid;
+use core::{cmp, ops::Deref};
 
-use std::collections::HashSet;
+use bitcoin::blockdata::transaction::Transaction;
 
 /// 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);
+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.
+	///
+	/// 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.
+	///
+	/// 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.
+	///
+	/// 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,
 }
 
@@ -41,105 +61,75 @@ pub enum ConfirmationTarget {
 ///
 /// Note that all of the functions implemented here *must* be reentrant-safe (obviously - they're
 /// called from inside the library in response to chain events, P2P events, or timer events).
-pub trait FeeEstimator: Sync + Send {
+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,
+/// 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).
+///
+/// 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;
 
-	// 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>,
+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)
+	}
 
-	watched_outpoints: HashSet<(Txid, u32)>,
+	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,
+		)
+	}
 }
 
-impl ChainWatchedUtil {
-	/// Constructs an empty (watches nothing) ChainWatchedUtil
-	pub fn new() -> Self {
-		Self {
-			watch_all: false,
-			watched_txn: HashSet::new(),
-			watched_outpoints: HashSet::new(),
-		}
+#[cfg(test)]
+mod tests {
+	use super::{FEERATE_FLOOR_SATS_PER_KW, LowerBoundedFeeEstimator, ConfirmationTarget, FeeEstimator};
+
+	struct TestFeeEstimator {
+		sat_per_kw: u32,
 	}
 
-	/// 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())
+	impl FeeEstimator for TestFeeEstimator {
+		fn get_est_sat_per_1000_weight(&self, _: ConfirmationTarget) -> u32 {
+			self.sat_per_kw
 		}
 	}
 
-	/// 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)
-	}
+	#[test]
+	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);
 
-	/// 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
+		assert_eq!(fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background), FEERATE_FLOOR_SATS_PER_KW);
 	}
 
-	/// 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
+	#[test]
+	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);
 	}
 }