Return refs from build_commitment_transaction, removing clone()s

Author: TheBlueMatt

src/ln/channel.rs

@@ -751,7 +751,7 @@ impl Channel {
 	/// generated by the peer which proposed adding the HTLCs, and thus we need to understand both
 	/// which peer generated this transaction and "to whom" this transaction flows.
 	#[inline]
-	fn build_commitment_transaction(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, feerate_per_kw: u64) -> (Transaction, Vec<(HTLCOutputInCommitment, Option<HTLCSource>)>) {
+	fn build_commitment_transaction(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, feerate_per_kw: u64) -> (Transaction, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>) {
 		let obscured_commitment_transaction_number = self.get_commitment_transaction_number_obscure_factor() ^ (INITIAL_COMMITMENT_NUMBER - commitment_number);
 
 		let txins = {
@@ -765,7 +765,7 @@ impl Channel {
 			ins
 		};
 
-		let mut txouts: Vec<(TxOut, Option<(HTLCOutputInCommitment, Option<HTLCSource>)>)> = Vec::with_capacity(self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len() + 2);
+		let mut txouts: Vec<(TxOut, Option<(HTLCOutputInCommitment, Option<&HTLCSource>)>)> = Vec::with_capacity(self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len() + 2);
 
 		let dust_limit_satoshis = if local { self.our_dust_limit_satoshis } else { self.their_dust_limit_satoshis };
 		let mut remote_htlc_total_msat = 0;
@@ -830,7 +830,7 @@ impl Channel {
 			};
 
 			if include {
-				add_htlc_output!(htlc, true, Some(htlc.source.clone()));
+				add_htlc_output!(htlc, true, Some(&htlc.source));
 				local_htlc_total_msat += htlc.amount_msat;
 			} else {
 				match htlc.state {
@@ -901,7 +901,7 @@ impl Channel {
 		transaction_utils::sort_outputs(&mut txouts);
 
 		let mut outputs: Vec<TxOut> = Vec::with_capacity(txouts.len());
-		let mut htlcs_used: Vec<(HTLCOutputInCommitment, Option<HTLCSource>)> = Vec::with_capacity(txouts.len());
+		let mut htlcs_used: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::with_capacity(txouts.len());
 		for (idx, out) in txouts.drain(..).enumerate() {
 			outputs.push(out.0);
 			if let Some(mut out_htlc) = out.1 {
@@ -1668,7 +1668,11 @@ impl Channel {
 			self.feerate_per_kw
 		};
 
-		let mut local_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, feerate_per_kw);
+		let mut local_commitment_tx = {
+			let mut commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, feerate_per_kw);
+			let htlcs_cloned: Vec<_> = commitment_tx.1.drain(..).map(|htlc_pair| (htlc_pair.0, htlc_pair.1.map(|source| (*source).clone()))).collect();
+			(commitment_tx.0, htlcs_cloned)
+		};
 		let local_commitment_txid = local_commitment_tx.0.txid();
 		let local_sighash = Message::from_slice(&bip143::SighashComponents::new(&local_commitment_tx.0).sighash_all(&local_commitment_tx.0.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap();
 		secp_check!(self.secp_ctx.verify(&local_sighash, &msg.signature, &self.their_funding_pubkey.unwrap()), "Invalid commitment tx signature from peer");
@@ -1692,19 +1696,19 @@ impl Channel {
 		new_local_commitment_txn.push(local_commitment_tx.0.clone());
 
 		let mut htlcs_and_sigs = Vec::with_capacity(local_commitment_tx.1.len());
-		for (idx, &(ref htlc, ref htlc_source)) in local_commitment_tx.1.iter().enumerate() {
-			let mut htlc_tx = self.build_htlc_transaction(&local_commitment_txid, htlc, true, &local_keys, feerate_per_kw);
+		for (idx, (htlc, htlc_source)) in local_commitment_tx.1.drain(..).enumerate() {
+			let mut htlc_tx = self.build_htlc_transaction(&local_commitment_txid, &htlc, true, &local_keys, feerate_per_kw);
 			let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &local_keys);
 			let htlc_sighash = Message::from_slice(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]).unwrap();
 			secp_check!(self.secp_ctx.verify(&htlc_sighash, &msg.htlc_signatures[idx], &local_keys.b_htlc_key), "Invalid HTLC tx signature from peer");
 			let htlc_sig = if htlc.offered {
-				let htlc_sig = self.sign_htlc_transaction(&mut htlc_tx, &msg.htlc_signatures[idx], &None, htlc, &local_keys)?;
+				let htlc_sig = self.sign_htlc_transaction(&mut htlc_tx, &msg.htlc_signatures[idx], &None, &htlc, &local_keys)?;
 				new_local_commitment_txn.push(htlc_tx);
 				htlc_sig
 			} else {
-				self.create_htlc_tx_signature(&htlc_tx, htlc, &local_keys)?.1
+				self.create_htlc_tx_signature(&htlc_tx, &htlc, &local_keys)?.1
 			};
-			htlcs_and_sigs.push(((*htlc).clone(), msg.htlc_signatures[idx], htlc_sig, (*htlc_source).clone()));
+			htlcs_and_sigs.push((htlc, msg.htlc_signatures[idx], htlc_sig, htlc_source));
 		}
 
 		let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &self.build_local_commitment_secret(self.cur_local_commitment_transaction_number - 1));
@@ -3232,7 +3236,7 @@ impl Channel {
 		}
 
 		let remote_keys = self.build_remote_transaction_keys()?;
-		let remote_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, true, feerate_per_kw);
+		let mut remote_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, true, feerate_per_kw);
 		let remote_commitment_txid = remote_commitment_tx.0.txid();
 		let remote_sighash = Message::from_slice(&bip143::SighashComponents::new(&remote_commitment_tx.0).sighash_all(&remote_commitment_tx.0.input[0], &funding_script, self.channel_value_satoshis)[..]).unwrap();
 		let our_sig = self.secp_ctx.sign(&remote_sighash, &self.local_keys.funding_key);
@@ -3247,11 +3251,12 @@ impl Channel {
 			htlc_sigs.push(self.secp_ctx.sign(&htlc_sighash, &our_htlc_key));
 		}
 
+		let htlcs_no_ref = remote_commitment_tx.1.drain(..).map(|htlc_pair| (htlc_pair.0, htlc_pair.1.map(|source| source.clone()))).collect();
 		Ok((msgs::CommitmentSigned {
 			channel_id: self.channel_id,
 			signature: our_sig,
 			htlc_signatures: htlc_sigs,
-		}, remote_commitment_tx))
+		}, (remote_commitment_tx.0, htlcs_no_ref)))
 	}
 
 	/// Adds a pending outbound HTLC to this channel, and creates a signed commitment transaction
@@ -3960,11 +3965,15 @@ mod tests {
 		let htlc_basepoint = PublicKey::from_secret_key(&secp_ctx, &chan.local_keys.htlc_base_key);
 		let keys = TxCreationKeys::new(&secp_ctx, &per_commitment_point, &delayed_payment_base, &htlc_basepoint, &chan.their_revocation_basepoint.unwrap(), &chan.their_payment_basepoint.unwrap(), &chan.their_htlc_basepoint.unwrap()).unwrap();
 
-		let mut unsigned_tx: (Transaction, Vec<(HTLCOutputInCommitment, Option<HTLCSource>)>);
+		let mut unsigned_tx: (Transaction, Vec<HTLCOutputInCommitment>);
 
 		macro_rules! test_commitment {
 			( $their_sig_hex: expr, $our_sig_hex: expr, $tx_hex: expr) => {
-				unsigned_tx = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, chan.feerate_per_kw);
+				unsigned_tx = {
+					let mut tx = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, chan.feerate_per_kw);
+					let htlcs = tx.1.drain(..).map(|htlc_pair| htlc_pair.0).collect();
+					(tx.0, htlcs)
+				};
 				let their_signature = Signature::from_der(&secp_ctx, &hex::decode($their_sig_hex).unwrap()[..]).unwrap();
 				let sighash = Message::from_slice(&bip143::SighashComponents::new(&unsigned_tx.0).sighash_all(&unsigned_tx.0.input[0], &chan.get_funding_redeemscript(), chan.channel_value_satoshis)[..]).unwrap();
 				secp_ctx.verify(&sighash, &their_signature, &chan.their_funding_pubkey.unwrap()).unwrap();
@@ -3980,7 +3989,7 @@ mod tests {
 			( $htlc_idx: expr, $their_sig_hex: expr, $our_sig_hex: expr, $tx_hex: expr ) => {
 				let remote_signature = Signature::from_der(&secp_ctx, &hex::decode($their_sig_hex).unwrap()[..]).unwrap();
 
-				let (ref htlc, _) = unsigned_tx.1[$htlc_idx];
+				let ref htlc = unsigned_tx.1[$htlc_idx];
 				let mut htlc_tx = chan.build_htlc_transaction(&unsigned_tx.0.txid(), &htlc, true, &keys, chan.feerate_per_kw);
 				let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
 				let htlc_sighash = Message::from_slice(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]).unwrap();