Rename CommitmentTransaction.feerate_per_kw()

tankyleo · tankyleo · commit d14ea231100f · 2025-09-05T00:30:51.000Z
Use `negotiated_feerate_per_kw()` to underscore that this is the feerate
we negotiated with our peer, not the actual feerate of the commitment
transaction. The feerate of the actual commitment transaction may be
higher.
diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
@@ -367,7 +367,7 @@ fn write_legacy_holder_commitment_data<W: Writer>(
 
 	let txid = trusted_tx.txid();
 	let to_self_value_sat = commitment_tx.to_broadcaster_value_sat();
-	let feerate_per_kw = trusted_tx.feerate_per_kw();
+	let feerate_per_kw = trusted_tx.negotiated_feerate_per_kw();
 	let revocation_key = &tx_keys.revocation_key;
 	let a_htlc_key = &tx_keys.broadcaster_htlc_key;
 	let b_htlc_key = &tx_keys.countersignatory_htlc_key;
@@ -3461,7 +3461,7 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 		if !commitment_tx.trust().channel_type_features().supports_anchor_zero_fee_commitments() {
 			// We populate this field for downgrades
 			self.initial_counterparty_commitment_info = Some((commitment_tx.per_commitment_point(),
-				commitment_tx.feerate_per_kw(), commitment_tx.to_broadcaster_value_sat(), commitment_tx.to_countersignatory_value_sat()));
+				commitment_tx.negotiated_feerate_per_kw(), commitment_tx.to_broadcaster_value_sat(), commitment_tx.to_countersignatory_value_sat()));
 
 			#[cfg(debug_assertions)] {
 				let rebuilt_commitment_tx = self.initial_counterparty_commitment_tx().unwrap();
@@ -3668,7 +3668,9 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 				{
 					return Err("Per-commitment-point mismatch");
 				}
-				if commitment_tx.feerate_per_kw() != other_commitment_tx.feerate_per_kw() {
+				if commitment_tx.negotiated_feerate_per_kw()
+					!= other_commitment_tx.negotiated_feerate_per_kw()
+				{
 					return Err("Commitment fee rate mismatch");
 				}
 				let nondust_htlcs = commitment_tx.nondust_htlcs();
@@ -4834,7 +4836,7 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitorImpl<Signer> {
 				commitment_txid: tx.txid(),
 				per_commitment_number: tx.commitment_number(),
 				per_commitment_point: tx.per_commitment_point(),
-				feerate_per_kw: tx.feerate_per_kw(),
+				feerate_per_kw: tx.negotiated_feerate_per_kw(),
 				htlc: htlc.clone(),
 				preimage,
 				counterparty_sig: *counterparty_sig,
diff --git a/lightning/src/chain/onchaintx.rs b/lightning/src/chain/onchaintx.rs
@@ -1397,7 +1397,7 @@ mod tests {
 						commitment_txid: holder_commit_txid,
 						per_commitment_number: holder_commit.commitment_number(),
 						per_commitment_point: holder_commit.per_commitment_point(),
-						feerate_per_kw: holder_commit.feerate_per_kw(),
+						feerate_per_kw: holder_commit.negotiated_feerate_per_kw(),
 						htlc: htlc.clone(),
 						preimage: None,
 						counterparty_sig: *counterparty_sig,
diff --git a/lightning/src/chain/package.rs b/lightning/src/chain/package.rs
@@ -528,7 +528,7 @@ impl HolderHTLCOutput {
 				commitment_txid: trusted_tx.txid(),
 				per_commitment_number: trusted_tx.commitment_number(),
 				per_commitment_point: trusted_tx.per_commitment_point(),
-				feerate_per_kw: trusted_tx.feerate_per_kw(),
+				feerate_per_kw: trusted_tx.negotiated_feerate_per_kw(),
 				htlc: htlc.clone(),
 				preimage: self.preimage.clone(),
 				counterparty_sig: *counterparty_sig,
@@ -1893,7 +1893,7 @@ mod tests {
 						commitment_txid: trusted_tx.txid(),
 						per_commitment_number: trusted_tx.commitment_number(),
 						per_commitment_point: trusted_tx.per_commitment_point(),
-						feerate_per_kw: trusted_tx.feerate_per_kw(),
+						feerate_per_kw: trusted_tx.negotiated_feerate_per_kw(),
 						htlc,
 						preimage: Some(preimage),
 						counterparty_sig: commitment_tx.counterparty_htlc_sigs[0].clone(),
@@ -1930,7 +1930,7 @@ mod tests {
 						commitment_txid: trusted_tx.txid(),
 						per_commitment_number: trusted_tx.commitment_number(),
 						per_commitment_point: trusted_tx.per_commitment_point(),
-						feerate_per_kw: trusted_tx.feerate_per_kw(),
+						feerate_per_kw: trusted_tx.negotiated_feerate_per_kw(),
 						htlc,
 						preimage: None,
 						counterparty_sig: commitment_tx.counterparty_htlc_sigs[0].clone(),
diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs
@@ -1982,8 +1982,11 @@ impl CommitmentTransaction {
 		self.to_countersignatory_value_sat.to_sat()
 	}
 
-	/// The feerate paid per 1000-weight-unit in this commitment transaction.
-	pub fn feerate_per_kw(&self) -> u32 {
+	/// The feerate paid per 1000-weight-unit we negotiated with our
+	/// peer for this commitment transaction. Note that the actual
+	/// feerate of the commitment transaction may be higher than the
+	/// negotiated feerate.
+	pub fn negotiated_feerate_per_kw(&self) -> u32 {
 		self.feerate_per_kw
 	}
 
diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
@@ -4611,7 +4611,7 @@ where
 		#[cfg(any(test, fuzzing))]
 		{
 			let PredictedNextFee { predicted_feerate, predicted_nondust_htlc_count, predicted_fee_sat } = *funding.next_local_fee.lock().unwrap();
-			if predicted_feerate == commitment_data.tx.feerate_per_kw() && predicted_nondust_htlc_count == commitment_data.tx.nondust_htlcs().len() {
+			if predicted_feerate == commitment_data.tx.negotiated_feerate_per_kw() && predicted_nondust_htlc_count == commitment_data.tx.nondust_htlcs().len() {
 				assert_eq!(predicted_fee_sat, commitment_data.stats.commit_tx_fee_sat);
 			}
 		}
@@ -4623,7 +4623,7 @@ where
 		let holder_keys = commitment_data.tx.trust().keys();
 		for (htlc, counterparty_sig) in commitment_data.tx.nondust_htlcs().iter().zip(msg.htlc_signatures.iter()) {
 			assert!(htlc.transaction_output_index.is_some());
-			let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_data.tx.feerate_per_kw(),
+			let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_data.tx.negotiated_feerate_per_kw(),
 				funding.get_counterparty_selected_contest_delay().unwrap(), &htlc, funding.get_channel_type(),
 				&holder_keys.broadcaster_delayed_payment_key, &holder_keys.revocation_key);
 
@@ -11877,7 +11877,7 @@ where
 				htlc_outputs,
 				commitment_number: self.context.counterparty_next_commitment_transaction_number,
 				their_per_commitment_point: self.context.counterparty_next_commitment_point.unwrap(),
-				feerate_per_kw: Some(counterparty_commitment_tx.feerate_per_kw()),
+				feerate_per_kw: Some(counterparty_commitment_tx.negotiated_feerate_per_kw()),
 				to_broadcaster_value_sat: Some(counterparty_commitment_tx.to_broadcaster_value_sat()),
 				to_countersignatory_value_sat: Some(counterparty_commitment_tx.to_countersignatory_value_sat()),
 			}
@@ -11940,7 +11940,7 @@ where
 		#[cfg(any(test, fuzzing))]
 		{
 			let PredictedNextFee { predicted_feerate, predicted_nondust_htlc_count, predicted_fee_sat } = *funding.next_remote_fee.lock().unwrap();
-			if predicted_feerate == counterparty_commitment_tx.feerate_per_kw() && predicted_nondust_htlc_count == counterparty_commitment_tx.nondust_htlcs().len() {
+			if predicted_feerate == counterparty_commitment_tx.negotiated_feerate_per_kw() && predicted_nondust_htlc_count == counterparty_commitment_tx.nondust_htlcs().len() {
 				assert_eq!(predicted_fee_sat, commitment_data.stats.commit_tx_fee_sat);
 			}
 		}
@@ -12004,7 +12004,7 @@ where
 					debug_assert_eq!(htlc_signatures.len(), trusted_tx.nondust_htlcs().len());
 					for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(trusted_tx.nondust_htlcs()) {
 						log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
-							encode::serialize_hex(&chan_utils::build_htlc_transaction(&trusted_tx.txid(), trusted_tx.feerate_per_kw(), funding.get_holder_selected_contest_delay(), htlc, funding.get_channel_type(), &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
+							encode::serialize_hex(&chan_utils::build_htlc_transaction(&trusted_tx.txid(), trusted_tx.negotiated_feerate_per_kw(), funding.get_holder_selected_contest_delay(), htlc, funding.get_channel_type(), &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
 							encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, funding.get_channel_type(), &counterparty_keys)),
 							log_bytes!(counterparty_keys.broadcaster_htlc_key.to_public_key().serialize()),
 							log_bytes!(htlc_sig.serialize_compact()[..]), &self.context.channel_id());
@@ -15786,7 +15786,7 @@ mod tests {
 						commitment_txid: trusted_tx.txid(),
 						per_commitment_number: trusted_tx.commitment_number(),
 						per_commitment_point: trusted_tx.per_commitment_point(),
-						feerate_per_kw: trusted_tx.feerate_per_kw(),
+						feerate_per_kw: trusted_tx.negotiated_feerate_per_kw(),
 						htlc: htlc.clone(),
 						preimage: preimage.clone(),
 						counterparty_sig: *htlc_counterparty_sig,
diff --git a/lightning/src/sign/mod.rs b/lightning/src/sign/mod.rs
@@ -1464,7 +1464,7 @@ impl EcdsaChannelSigner for InMemorySigner {
 			let chan_type = &channel_parameters.channel_type_features;
 			let htlc_tx = chan_utils::build_htlc_transaction(
 				&commitment_txid,
-				commitment_tx.feerate_per_kw(),
+				commitment_tx.negotiated_feerate_per_kw(),
 				holder_selected_contest_delay,
 				htlc,
 				chan_type,

Original file line number	Diff line number	Diff line change
`@@ -1982,8 +1982,11 @@ impl CommitmentTransaction {`
`1982`	`1982`	`self.to_countersignatory_value_sat.to_sat()`
`1983`	`1983`	`}`
`1984`	`1984`
`1985`		`- /// The feerate paid per 1000-weight-unit in this commitment transaction.`
`1986`		`- pub fn feerate_per_kw(&self) -> u32 {`
	`1985`	`+ /// The feerate paid per 1000-weight-unit we negotiated with our`
	`1986`	`+ /// peer for this commitment transaction. Note that the actual`
	`1987`	`+ /// feerate of the commitment transaction may be higher than the`
	`1988`	`+ /// negotiated feerate.`
	`1989`	`+ pub fn negotiated_feerate_per_kw(&self) -> u32 {`
`1987`	`1990`	`self.feerate_per_kw`
`1988`	`1991`	`}`
`1989`	`1992`