chore: refactor and unify LOCAL/REMOTE helpers for receivable_msat

lightningd/peer_control.c

@@ -509,92 +509,46 @@ static void json_add_sat_only(struct json_stream *result,
 				type_to_string(tmpctx, struct amount_msat, &msat));
 }
 
-/* Fee a commitment transaction would currently cost when spending */
-/* This is quite a lot of work to figure out what it would cost us! */
-static struct amount_sat commit_txfee_spend(const struct channel *channel,
-					   struct amount_msat spendable)
+/* Fee a commitment transaction would currently cost */
+static struct amount_sat commit_txfee(const struct channel *channel,
+				      struct amount_msat amount,
+				      enum side side)
 {
 	/* FIXME: make per-channel htlc maps! */
 	const struct htlc_in *hin;
 	struct htlc_in_map_iter ini;
 	const struct htlc_out *hout;
 	struct htlc_out_map_iter outi;
 	struct lightningd *ld = channel->peer->ld;
-	u32 local_feerate = get_feerate(channel->channel_info.fee_states,
-					channel->funder, LOCAL);
 	size_t num_untrimmed_htlcs = 0;
-
-	/* Assume we tried to spend "spendable" */
-	if (!htlc_is_trimmed(LOCAL, spendable,
-			     local_feerate, channel->our_config.dust_limit,
-			     LOCAL))
-		num_untrimmed_htlcs++;
-
-	for (hin = htlc_in_map_first(&ld->htlcs_in, &ini);
-	     hin;
-	     hin = htlc_in_map_next(&ld->htlcs_in, &ini)) {
-		if (hin->key.channel != channel)
-			continue;
-		if (!htlc_is_trimmed(REMOTE, hin->msat, local_feerate,
-				     channel->our_config.dust_limit,
-				     LOCAL))
-			num_untrimmed_htlcs++;
-	}
-	for (hout = htlc_out_map_first(&ld->htlcs_out, &outi);
-	     hout;
-	     hout = htlc_out_map_next(&ld->htlcs_out, &outi)) {
-		if (hout->key.channel != channel)
-			continue;
-		if (!htlc_is_trimmed(LOCAL, hout->msat, local_feerate,
-				     channel->our_config.dust_limit,
-				     LOCAL))
-			num_untrimmed_htlcs++;
-	}
-
-	/* Funder is conservative: makes sure it allows an extra HTLC
-	 * even if feerate increases 50% */
-	return commit_tx_base_fee(local_feerate + local_feerate / 2,
-				  num_untrimmed_htlcs + 1);
-}
-
-/* Fee a commitment transaction would currently cost when receiving */
-static struct amount_sat commit_txfee_recv(const struct channel *channel,
-					   struct amount_msat receivable)
-{
-	/* FIXME: make per-channel htlc maps! */
-	const struct htlc_in *hin;
-	struct htlc_in_map_iter ini;
-	const struct htlc_out *hout;
-	struct htlc_out_map_iter outi;
-	struct lightningd *ld = channel->peer->ld;
 	u32 feerate = get_feerate(channel->channel_info.fee_states,
-				  channel->funder, REMOTE);
-	size_t num_untrimmed_htlcs = 0;
-
-	/* Assume we tried to receive "receivable" */
-	if (!htlc_is_trimmed(REMOTE, receivable, feerate,
-			     channel->channel_info.their_config.dust_limit,
-			     REMOTE))
+				  channel->funder, side);
+	struct amount_sat dust_limit;
+	if (side == LOCAL)
+		dust_limit = channel->our_config.dust_limit;
+	if (side == REMOTE)
+		dust_limit = channel->channel_info.their_config.dust_limit;
+
+	/* Assume we tried to add "amount" */
+	if (!htlc_is_trimmed(side, amount, feerate, dust_limit, side))
 		num_untrimmed_htlcs++;
 
 	for (hin = htlc_in_map_first(&ld->htlcs_in, &ini);
 	     hin;
 	     hin = htlc_in_map_next(&ld->htlcs_in, &ini)) {
 		if (hin->key.channel != channel)
 			continue;
-		if (!htlc_is_trimmed(LOCAL, hin->msat, feerate,
-				     channel->channel_info.their_config.dust_limit,
-				     REMOTE))
+		if (!htlc_is_trimmed(!side, hin->msat, feerate, dust_limit,
+				     side))
 			num_untrimmed_htlcs++;
 	}
 	for (hout = htlc_out_map_first(&ld->htlcs_out, &outi);
 	     hout;
 	     hout = htlc_out_map_next(&ld->htlcs_out, &outi)) {
 		if (hout->key.channel != channel)
 			continue;
-		if (!htlc_is_trimmed(REMOTE, hout->msat, feerate,
-				     channel->channel_info.their_config.dust_limit,
-				     REMOTE))
+		if (!htlc_is_trimmed(side, hout->msat, feerate, dust_limit,
+				     side))
 			num_untrimmed_htlcs++;
 	}
 
@@ -604,7 +558,6 @@ static struct amount_sat commit_txfee_recv(const struct channel *channel,
 				  num_untrimmed_htlcs + 1);
 }
 
-
 static void subtract_offered_htlcs(const struct channel *channel,
 				   struct amount_msat *amount)
 {
@@ -771,7 +724,8 @@ static void json_add_channel(struct lightningd *ld,
 	/* If we're funder, subtract txfees we'll need to spend this */
 	if (channel->funder == LOCAL) {
 		if (!amount_msat_sub_sat(&spendable, spendable,
-					 commit_txfee_spend(channel, spendable)))
+					 commit_txfee(channel, spendable,
+						      LOCAL)))
 			spendable = AMOUNT_MSAT(0);
 	}
 
@@ -802,7 +756,8 @@ static void json_add_channel(struct lightningd *ld,
 	/* If they're funder, subtract txfees they'll need to spend this */
 	if (channel->funder == REMOTE) {
 		if (!amount_msat_sub_sat(&receivable, receivable,
-					 commit_txfee_recv(channel, receivable)))
+					 commit_txfee(channel,
+						      receivable, REMOTE)))
 			receivable = AMOUNT_MSAT(0);
 	}